Effect of Tumor Regression Grade on Survival and Disease-Free Interval in Patients Operated on for Locally Advanced Rectal Cancer.

INTRODUCTION: Colorectal cancer is the fourth leading cause of cancer-related death in both men and women in our population. In this regard, rectal cancer accounts for more than half of colorectal cancer deaths, and its incidence is expected to increase in the coming years. There have been significant changes in neoadjuvant therapy regimens, with promising results, as demonstrated by the recent RAPIDO and PRODIGE23 studies. Around 40% of patients diagnosed with locally advanced rectal cancer show some degree of response to neoadjuvant treatment, with complete tumor regression observed in up to one in five patients. MATERIALS AND METHODS: Retrospective observational study. A total of 181 patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy followed by surgery were analyzed. Clinical and pathological data were collected from the patients, including assessment of tumor regression through histopathological studies after surgery. The Mandard tumor regression grading system was used to categorize tumor response into different grades. RESULTS: The results showed a significant association between the degree of tumor regression and several important clinical outcomes. Specifically, patients with higher tumor regression had significantly better disease-free survival than those with less regression (p = 0.004). In addition, tumor regression was also correlated with the incidence of local recurrence (p = 0.018) and distant metastasis (p = 0.032). These associations suggest that tumor responsiveness to neoadjuvant therapy may influence the long-term progression of the disease. Regarding tumor deposits and the presence of lymphadenopathy, these factors were also found to be significantly associated with clinical outcomes. Patients with tumor deposits had a higher incidence of local recurrence (p = 0.025) and distant metastases (p = 0.041), while the presence of lymphadenopathy increased the risk of local recurrence (p = 0.013). These findings highlight the importance of evaluating not only tumor regression but also other pathological markers to predict prognosis and guide clinical management. CONCLUSIONS: The degree of tumor regression was not an independent predictor of survival compared to other variables such as nodal stage and presence of tumor deposits. This indicates that while tumor regression is an important factor, other elements also play a crucial role in determining the prognosis of patients with locally advanced rectal cancer. This study provides additional evidence for the importance of tumor regression, tumor deposits, and lymphadenopathy as predictors of clinical outcomes in patients with rectal cancer treated with neoadjuvant chemoradiotherapy.

Association of pathological response with long-term survival outcomes after neoadjuvant immunotherapy: A meta-analysis.

BACKGROUND: Complete pathological response (pCR) and major pathological response (MPR) have been proven to have a close association with improved event-free survival (EFS) and overall survival (OS) for patients accepting chemotherapy or chemoradiotherapy. However, further study focusing on neoadjuvant immunotherapy is limited. Here we provided an updated and comprehensive evaluation of the association between pathological response and long-term survival outcomes at patient level and trial level for neoadjuvant immunotherapy. METHODS: We systematically searched and assessed studies in PubMed, Embase, the Cochrane Library and relevant conference abstracts from inception to June 1, 2023. Studies reported EFS/OS results by pCR/MPR status were eligible. RESULTS: Forty-three studies comprising a total of 4100 patients were eligible for the analysis, which included 39 studies for the patient-level analysis and 5 randomized controlled trials for the trial-level analysis. Our results highlighted that pCR was associated with improved EFS (HR, 0.48 [95 % CI, 0.39-0.60]) and OS (HR, 0.55 [95 % CI, 0.41-0.74]). The magnitude of HRs by MPR status were similar to the results by pCR status (EFS HR, 0.31 [95 % CI, 0.18-0.53]) and OS HR, 0.43 [95 % CI, 0.19-0.96]). However, no association between pCR and EFS at trial level was found (P = 0.8, R2 = 0). CONCLUSION: Our meta-analysis demonstrates a strong association between pathological response and long-term survival outcomes at patient level across studies applying neoadjuvant immunotherapy in most solid tumors but we fail to validate the relationship at trial level. Therefore, an accepted surrogate endpoint applied to both patient and trial levels are waited for further search.

Case report: Pathological complete response of pregnancy associated pulmonary enteric adenocarcinoma to chemoradiotherapy.

Pulmonary enteric adenocarcinoma (PEAC) is a rare lung adenocarcinoma with morphological features similar to those of primary and metastatic colorectal adenocarcinoma. To date, only a few studies have reported the therapeutic effects of chemoradiotherapy on PEAC. This report describes the case of a 28-year-old woman with pregnancy-related PEAC who presented with left shoulder pain. A superior sulcus tumor was identified in the left thoracic cavity, and the biopsy indicated more than 50% intestinal differentiation components. Moreover, immunohistochemical staining revealed positive CDX2 and CK7 expression. Positron emission tomography-computed tomography, upper endoscopy, colonoscopy, and small intestinal capsule endoscopy revealed no gastrointestinal malignancies. The patient was diagnosed with locally advanced PEAC (clinical stage T4N0M0; stage IIIA). Therefore, the patient was treated with preoperative chemoradiotherapy and underwent gross total resection during surgery. Pathological evaluation of the specimen revealed no residual tumor, indicating that the chemoradiotherapy for PEAC was highly effective. One subsequent brain metastasis was also resected, and the patient has not experienced recurrence in 28 months since this resection and continues to be monitored regularly. This is the first pathologically confirmed report of the use of chemoradiotherapy (carboplatin [CBDCA] and paclitaxel [PTX]) for PEAC and its clinical efficacy. Unlike previous reports, the efficacy of this treatment is attributed to the use of PTX in preoperative chemotherapy and the p21- status of the patient, which may have increased sensitivity to chemoradiation therapy. Therefore, chemoradiotherapy (CBDCA + PTX) may be a viable treatment option for advanced intestinal lung adenocarcinoma.

Does complete pathological response increase perioperative morbidity risk in rectal cancer?

AIM: The optimal management of patients with clinical complete response after neoadjuvant treatment for rectal cancer is controversial. The aim of this study is to compare the morbidity between patients with locally advanced rectal cancer who have had a pathological complete response (pCR) or not after neoadjuvant chemoradiotherapy (NCRT) and total mesorectal excision (TME). The study hypothesis was that pCR may impact the surgical complication rate. METHOD: A retrospective cohort study was conducted of a prospectively maintained database in Australia and New Zealand, the Binational Colorectal Cancer Audit, that identified patients with locally advanced rectal cancer (<15 cm from anal verge) from 1 January 2007 to 31 December 2019. Patients were included if they had locally advanced rectal cancer and had undergone NCRT and proceeded to surgical resection. RESULTS: There were 4584 patients who satisfied the inclusion criteria, 65% being male. The mean age was 63 years and 11% had a pCR (ypT0N0). TME with anastomosis was performed in 67.8% of patients, and the majority of the cohort received long-course radiotherapy (81.7%). Both major and minor complications were higher in the TME without anastomosis group (17.3% vs. 14.7% and 30.6% vs. 20.8%, respectively), and the 30-day mortality was 1.31%. In the TME with anastomosis group, pCR did not contribute to higher rates of surgical complications, but male gender (p < 0.0012), age (p < 0.0001), preoperative N stage (p = 0.0092) and American Society of Anesthesologists (ASA) score ≥3 (p < 0.0002) did. In addition, pCR had no significant effect (p = 0.44) but male gender (p = 0.0047) and interval to surgery (p = 0.015) contributed to higher rates of anastomotic leak. In the TME without anastomosis cohort, the only variable that contributed to higher rates of complications was ASA score ≥3 (p = 0.033). CONCLUSION: Patients undergoing TME dissection for rectal cancer following NCRT showed no difference in complications whether they had achieved pCR or not.

Conversion surgery for stage IV gastric cancer with multiple liver metastases with a complete pathological response to S-1 plus oxaliplatin therapy.

Although patients with stage IV gastric cancer who respond well to systemic chemotherapy can be treated with gastrectomy, the prognosis of patients with multiple liver metastases is poor. We herein describe a patient with stage IV gastric cancer with multiple liver metastases who underwent conversion surgery after systemic treatment with S-1 plus oxaliplatin. The patient was a 62-year-old man. Upper gastrointestinal endoscopy revealed a 30-mm type 2 tumor in the greater curvature of the stomach at the anterior wall, and biopsy revealed a poorly differentiated adenocarcinoma. Imaging showed three suspected liver metastases in liver segment S8. The patient was judged to have gastric cancer, cStage IV (cT3N1M1(H)), and systemic chemotherapy was administered. He was treated with a total of six courses of chemotherapy. After re-evaluation, the primary tumor had shrunk significantly, and liver metastases could not be detected. Confirming no signs of seeding by laparoscopy, robot-assisted pylorus-preserving gastrectomy with D2 dissection and laparoscopic partial hepatic (S8) resection were performed. The patient was diagnosed with a complete pathological response. Conversion surgery is an option for stage IV gastric cancer when distant metastases are controlled with chemotherapy and when R0 resection is possible.

Prolonged interval to surgery following neoadjuvant chemoradiotherapy in locally advanced rectal cancer: A meta-analysis of randomized controlled trials.

BACKGROUND: Long-course neoadjuvant chemoradiotherapy (NCRT), followed by surgery after an interval of 6-8 weeks, represents standard of care for patients with locally advanced rectal cancer (LARC). Increasing this interval may improve rates of complete pathological response (pCR) and tumour downstaging. We performed a meta-analysis comparing standard (SI, within 8 weeks) versus longer (LI, after 8 weeks) interval from NCRT to surgery. METHODS: PubMed, Embase, and Cochrane databases were searched up to 31 August 2022. Randomized controlled trials (RCTs) comparing SI with LI after NCRT for LARC were included. The primary endpoint was pCR rate. Secondary endpoints included rates of R0 resection, circumferential resection margin positivity (+CRM), TME completeness, lymph node yield (LNY), operative duration, tumour downstaging (TD), sphincter preservation, mortality, postoperative complications, surgical site infection (SSI) and anastomotic leak (AL). Random effects models were used to calculate pooled effect size estimates. RESULTS: Four RCTs encompassing 867 patients were included. There were 539 males (62.1%). LI was associated with a higher pCR rate (OR 0.61, 95%CI â€‹= â€‹0.39-0.95, p â€‹= â€‹0.03), and more TD (OR 0.60, 95%CI â€‹= â€‹0.37-0.97, p â€‹= â€‹0.04) compared to SI. However, there was no difference in rates of R0 resection (p â€‹= â€‹0.87), +CRM (p â€‹= â€‹0.66), sphincter preservation (p â€‹= â€‹0.26), incomplete TME (p â€‹= â€‹0.49), LNY (p â€‹= â€‹0.55), SSI (p â€‹= â€‹0.33), AL (p â€‹= â€‹0.20), operative duration (p â€‹= â€‹0.07), mortality (p â€‹= â€‹0.89) or any surgical complication (p â€‹= â€‹0.91). CONCLUSIONS: A LI to surgery after NCRT for LARC increases pCR and TD rates. Local recurrence or survival were not assessed due to unavailable data. We recommend deferring TME until after an interval of 8 weeks following completion of NCRT.

Neoadjuvant chemotherapy with dose-dense MVAC in muscle-invasive bladder cancer: a tertiary center experience

Purpose Neoadjuvant chemotherapy in muscle-invasive bladder cancer (MIBC) patients has proven beneficial in overall survival. However, the optimal regimen is still a matter of debate. Materials and method In this retrospective analysis, we evaluate the results obtained in 42 patients treated in our center with 4 cycles of neoadjuvant dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (dd-MVAC) followed by radical cystectomy from August 2015 to October 2020. All patients had cT2 or higher non-metastatic MIBC. Clinical and pathological outcomes are reported. Results Of the 42 patients, 90.5% were men (n = 38) and the mean age was 65 years. All of them had ECOG 0–1 at diagnosis and most tumors had an initial clinical stage T2N0 (76%). Thirty-six patients (85.7%) completed 4 cycles of neoadjuvant treatment, and 21.4% required a dose reduction. The most frequent adverse event (AE) was grade 1–2 asthenia (81%), while neutropenia was the most frequent grade 3 or higher AE (38%). Complete pathological response (ypT0, ypN0) was achieved in 50% of patients (n = 21), and down-staging was observed in 57.1% (n = 24). Only one patient presented radiological progressive disease during neoadjuvant treatment (2.4%), and after a mean follow-up time of 31.5 months, 33.3% of patients experienced disease recurrence. Conclusions Neoadjuvant chemotherapy with 4 cycles of dd-MVAC is an effective regimen with high rates of pathological complete responses and down-staging along with an acceptable toxicity profile. DD-MVAC should be considered as an alternative to cisplatin and gemcitabine in patients with good clinical performance status (AU)

Stage III-IV thymic squamous cell carcinoma in complete pathological remission achieved with thymic cancer resection after immunotherapy combined with chemotherapeutic conversion therapy: a report of two cases from real-world data.

Background: Thymic carcinoma, a rare malignancy in the mediastinum, currently lacks standardized treatment options. Although surgery remains a crucial component among traditional therapeutic approaches, the potential benefits of radiotherapy and chemotherapy remain controversial. Nevertheless, a substantial number of patients are diagnosed with advanced tumor growth, posing challenges for achieving complete resection through surgical intervention and resulting in a poor prognosis. In light of the promising antitumor effects demonstrated by immunotherapy in various prevalent cancers, certain studies have shown favorable efficacy in advanced or recurrent thymic cancer cases. However, the incidence of adverse effects induced by immunotherapy in thymic cancer is notably higher compared to other tumor types, with severe and fatal complications being particularly significant. Consequently, there is an urgent need to address the crucial issue of patient selection for immunotherapy in thymic cancer. Case Description: In this study, we report on the treatment with programmed cell death protein 1 (PD-1) inhibitor therapy combined with chemotherapy conversion therapy for two patients diagnosed with stage III-IV thymic squamous cell carcinoma according to the Masaoka-Koga staging system. The aim of this study was to assess the effectiveness and safety of PD-1 inhibitor combined with chemotherapy conversion therapy in patients with thymic squamous cell carcinoma. Two patients in this cohort, one with stage III and another with stage IV disease, were deemed ineligible for upfront surgical resection. Puncture pathology confirmed the diagnosis of thymic squamous cell carcinoma. Both patients underwent transformation therapy using a combination of PD-1 inhibitors and chemotherapy. Tumor shrinkage was observed in both patients, enabling successful completion of surgery. Postoperative pathology revealed no residual tumor cells, indicating complete pathological remission. Notably, none of the patients experienced grade 3 or higher immunotherapy-related adverse reactions following immunotherapy. Conclusions: A combination of PD-1 inhibitors and chemotherapy followed by surgery demonstrated improved efficacy and enhanced safety for treating patients with Masaoka-Koga stage III-IV thymic squamous carcinoma and represents a potential novel therapeutic alternative for this disease.

Complete Primary Pathological Response Following Neoadjuvant Treatment and Radical Resection for Pancreatic Ductal Adenocarcinoma.

INTRODUCTION: Neoadjuvant treatment (NAT) for borderline (BD) or locally advanced (LA) primary pancreatic cancer (PDAC) is now a widely adopted approach. We present a case series of patients who have achieved a complete pathological response of the primary tumour on final histology following neoadjuvant chemotherapy +/- chemoradiation and radical surgery. METHODS: Patients who underwent radical pancreatic resection following neoadjuvant treatment between March 2006 and March 2023 at a single institution were identified by retrospective case note review of a prospectively maintained database. RESULTS: Ten patients were identified to have a complete primary pathological response (ypT0) on postoperative histology. Before treatment, five patients were considered BD and five were LA according to National Comprehensive Cancer Network guidelines. All patients underwent staging Computed Tomography (CT) and nine underwent 18Fluorodeoxyglucose Positron Emission Tomography (18FDG-PET/CT) imaging, with a mean maximum standardized uptake value (SUVmax) of the primary lesion at 6.14 ± 1.98 units. All patients received neoadjuvant chemotherapy, and eight received further chemoradiotherapy prior to resection. Mean pre- and post-neoadjuvant treatment serum Ca19-9 was 148.0 ± 146.3 IU/L and 18.0 ± 18.7 IU/L, respectively (p = 0.01). The mean duration of NAT was 5.6 ± 1.7 months. The mean time from completion of NAT to surgery was 13.1 ± 8.3 weeks. The mean lymph node yield was 21.1 ± 10.4 nodes, with one patient found to have 1 lymph node involved. All resections were reported to be R0. The mean length of stay was 11.8 ± 6.2 days. At the time of analysis, one death was reported at 35 months postoperatively. Two cases of recurrence were reported at 16 months (surgical bed) and 33 months (pulmonary). All other patients remain alive and under active surveillance. The current overall survival is 26.6 ± 20.7 months and counting. CONCLUSIONS: Complete primary pathological response is uncommon but possible following neoadjuvant treatment in patients with PDAC. Further work to identify the common denominator within this unique cohort may lead to advances in the therapeutic approach and offer hope for patients diagnosed with borderline or locally advanced pancreatic ductal adenocarcinoma.

Predictive factors for complete pathological response in hormone receptor-negative breast cancer patients undergoing neoadjuvant chemotherapy.

Complete pathological response (pCR) is a pivotal predictor of enhanced disease-free and overall survival rates in breast cancer patients. Accurate prediction of pCR is therefore of paramount clinical significance. This retrospective study aimed to delineate the factors associated with pCR through a comprehensive analysis encompassing clinical, pathological, and immunohistochemical profiling of patients diagnosed with hormone receptor-negative invasive ductal carcinomas. The study cohort was composed of 73 female patients. The cases were reviewed retrospectively using data from University Hospital "Tsaritsa Yoanna" in Sofia, spanning the ten-year period from 2010 to 2020. Univariate analyses demonstrated that patients diagnosed with a higher disease stage, specifically stage IIIb, exhibited a notable association with an unfavorable response to neoadjuvant chemotherapy (NCT) [OR 4.5455 (95%CI 1.6810 - 12.2910); p = 0.0029]. Invasive carcinomas containing a ductal carcinoma in situ (DCIS) component [OR 0.3333 (95%CI 0.1226 - 0.9063); p = 0.0313] or were classified as poorly differentiated [OR 0.3056 (95%CI 0.1159 - 0.8055); p = 0.0165] demonstrated an enhanced likelihood of achieving pCR. Tumors expressing CD10 [OR 0.1452 (95%CI 0.0515 - 0.4093); p = 0.0003] and tumors lacking EGFR [OR 3.9722 (95%CI 1.4691 - 10.7399); p = 0.0066] exhibited a markedly elevated rate of pCR. Multivariate regression analysis supported findings. In conclusion, hormone receptor-negative breast tumors stand to benefit from increased pCR rates if they encompass a DCIS component and exhibit CD10 expression while lacking EGFR expression. These findings underscore the importance of comprehensive profiling in predicting pCR outcomes in hormone receptor-negative breast cancer patients undergoing neoadjuvant chemotherapy.

Neoadjuvant chemotherapy with dose-dense MVAC in muscle-invasive bladder cancer: a tertiary center experience.

PURPOSE: Neoadjuvant chemotherapy in muscle-invasive bladder cancer (MIBC) patients has proven beneficial in overall survival. However, the optimal regimen is still a matter of debate. MATERIALS AND METHODS: In this retrospective analysis, we evaluate the results obtained in 42 patients treated in our center with 4 cycles of neoadjuvant dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (dd-MVAC) followed by radical cystectomy from August 2015 to October 2020. All patients had cT2 or higher non-metastatic MIBC. Clinical and pathological outcomes are reported. RESULTS: Of the 42 patients, 90.5% were men (n = 38) and the mean age was 65 years. All of them had ECOG 0-1 at diagnosis and most tumors had an initial clinical stage T2N0 (76%). Thirty-six patients (85.7%) completed 4 cycles of neoadjuvant treatment, and 21.4% required a dose reduction. The most frequent adverse event (AE) was grade 1-2 asthenia (81%), while neutropenia was the most frequent grade 3 or higher AE (38%). Complete pathological response (ypT0, ypN0) was achieved in 50% of patients (n = 21), and down-staging was observed in 57.1% (n = 24). Only one patient presented radiological progressive disease during neoadjuvant treatment (2.4%), and after a mean follow-up time of 31.5 months, 33.3% of patients experienced disease recurrence. CONCLUSIONS: Neoadjuvant chemotherapy with 4 cycles of dd-MVAC is an effective regimen with high rates of pathological complete responses and down-staging along with an acceptable toxicity profile. DD-MVAC should be considered as an alternative to cisplatin and gemcitabine in patients with good clinical performance status.

Complete pathological remission and tertiary lymphoid structures are associated with the efficacy of resectable NSCLC receiving neoadjuvant chemoimmunotherapy: A double-center retrospective study.

This study aimed to investigate the relationship between complete pathological remission (PCR), tertiary lymphoid structure (TLS) maturation and expression and clinical outcomes of patients with resectable non-small cell lung cancer (NSCLC) receiving neoadjuvant chemoimmunotherapy. Totally 80 patients with resectable NSCLC (stage IB-IIIB) receiving neoadjuvant chemoimmunotherapy were analyzed. We used the Kaplan-Meier method to plot survival curves and the log-rank test to compare differences. Among all patients included, 45 patients (56.25%) achieved major pathological response (MPR), including 30 patients (37.50%) with PCR. The proportion of patients diagnosed with stage IB, II, IIIA and IIIB was 1.25%, 10.00%, 52.50% and 36.25%, respectively. We divided patients into PCR group and non-PCR group respectively according to whether they achieved PCR. We found that patients achieving PCR had significantly improved disease-free survival (DFS) (mDFS: NR vs. 20.24 months, P = .020). TLS expression was low in 43 cases (53.75%) and high in 37 cases (46.25%). TLS maturation was low in 55 cases (68.75%) and high in 25 cases (31.25%). The DFS of patients with TLS high-maturation (34.07 vs. 22.30 months, P = .024) and TLS high-expression (34.07 vs. 22.30 months, P = .041) was significantly longer. In most subgroups, the PCR, TLS high-maturation and TLS high-expression group respectively achieved a better clinical outcome relative to the non-PCR, TLS low-maturation and TLS low-expression group. In patients with resectable NSCLC receiving neoadjuvant chemoimmunotherapy, the acquirement of PCR may predict better DFS. In addition, high expression and maturation of TLS may be prognostic factors.

Survival outcomes seen with neoadjuvant chemotherapy in the management of locally advanced inflammatory breast cancer (IBC) versus matched controls.

Inflammatory breast cancer (IBC) poses an ongoing challenge as rates of disease recurrence and mortality remain high compared to stage-matched controls. However, frontline therapy has evolved through the years, including the widespread use of neoadjuvant chemotherapy (NAC) given the prognostic importance of pathologic complete response (pCR). Due to these sweeping changes, we need new data to assess current recurrence and survival outcomes for locally advanced IBC in the context of matched non-inflammatory controls. We conducted a retrospective analysis of institutional IBC data from 2010 to 2016 with the primary objective of comparing overall survival (OS), relapse-free survival (RFS), and distant relapse-free survival (DRFS). We matched IBC patients to non-inflammatory controls based on age, receptor status, tumor grade, clinical stage, and receipt of prior NAC. Secondary objectives included assessing pCR rates and identifying prognostic factors. Among NAC recipients, we observed similar pCR rates (47.6 % vs. 49.4 %, p = 0.88) between IBC (n = 84) and matched non-IBC (n = 81) cohorts. However, we noted a significant worsening of OS (p = 0.0001), RFS (p = 0.0001), and DRFS (p = 0.001) in the IBC group. Specifically, 5-year OS in the IBC cohort was 58.9 % vs. 86.7 % for matched controls (p = 0.0003). Older age was a weak negative predictor for OS (HR 1.03, p = 0.001) and RFS (HR 1.02, p = 0.01). For DRFS, older age was also a weak negative predictor (HR 1.02, p = 0.02), whereas the use of NAC was a positive predictor (HR 0.47, p = 0.02). Despite no clear difference in pCR, survival outcomes remain poor for IBC compared to matched non-inflammatory controls.

Pancreatic ductal adenocarcinoma complete regression after preoperative chemotherapy: Surgical results in a small series.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) becomes a systemic disease from an early stage. Complete surgical resection remains the only validated and potentially curative treatment; disappointingly only 20% of patients present with a resectable tumour. Although a complete pathological regression (pCR) after the preoperative chemotherapy could intuitively lead to better outcomes and prolonged survival some reports highlighted significant rates of recurrence. CASES PRESENTATION: We describe three cases of pCR following preoperative chemotherapy for PDAC. The first two cases received neoadjuvant mFOLFIRINOX and PAX-G scheme for borderline resectable PDAC. Recurrence appeared 9 and 12 months after surgery. Although both patients started adjuvant therapy straight after the diagnosis of recurrence, the disease rapidly progressed and led them to death 12 and 15 months after surgery. The third case was characterized by germline BRCA2 mutation. The patient presented with PDAC of the body, intrapancreatic biliary stenosis and suspected peritoneal metastasis. One year later, after first and second-line chemotherapy, she underwent explorative laparoscopy and total spleno-pancreatectomy without evidence of viable tumour cells in the surgical specimen. At six months she is recurrence-free. CONCLUSIONS: Very few reports describe a complete pathological response following preoperative chemotherapy in pancreatic cancer. We observed three cases in the last three years with disappointing oncological results. Further investigations are needed to predict PDAC prognosis in pCR after chemotherapy.

Omitting Sentinel Lymph Node Biopsy after Neoadjuvant Systemic Therapy for Clinically Node Negative HER2 Positive and Triple Negative Breast Cancer: A Pooled Analysis.

Recent advances in systemic treatment for breast cancer have been underpinned by recognising and exploiting subtype-specific vulnerabilities to achieve higher rates of pathologic complete response (pCR) after neo-adjuvant systemic therapy (NAST). This down-staging of disease has permitted safe surgical de-escalation in patients who respond well. Triple-negative (TNBC) or HER2-positive breast cancer is most likely to achieve complete radiological response (rCR) and pCR after NAST. Hence, for selected patients, particularly those who are clinically node-negative (cN0) at diagnosis, the probability of disease in the sentinel node after NAST could be low enough to justify omitting axillary surgery. The aim of this pooled analysis was to determine the rate of sentinel node positivity (ypN+) in patients with TNBC or HER2-positive breast cancer who were initially cN0, achieving rCR and/or pCR in the breast after NAST. MedLine was searched using appropriate search terms. Five studies (N = 3834) were included in the pooled analysis, yielding a pooled ypN+ rate of 2.16% (95% CI: 1.70-2.63). This is significantly lower than the acceptable false negative rate of sentinel lymph node biopsy (SLNB) and supports consideration of omission of SLNB in this subset of patients.

Radioquimioterapia neoadyuvante en cáncer de recto: Relevancia clínica del downstaging y la respuesta patológica completa

Antecedentes: La radioquimioterapia neoadyuvante es uno de los pilares del tratamiento del cáncer de recto localmente avanzado. La neoadyuvancia ha demostrado disminuir la recidiva local, generando también un downstaging tumoral, llegando incluso a una respuesta patológica completa (RPC), esta última relacionada con una mejor sobrevida global (SG) y sobrevida libre de enfermedad (SLE). Objetivo: Reportar los resultados anátomo-patológicos del tratamiento con radioquimioterapia en cáncer de recto, analizando su relación con la SG y la SLE. Material y Método: Estudio de cohorte prospectivo. Se analiza base de datos de cirugías coloproctológicas del Hospital Clínico de la Universidad de Chile, entre los años 20042019, incluyendo pacientes con cáncer de recto medio y bajo localmente avanzados, los cuales recibieron neoadyuvancia y posteriormente cirugía. Se realizó el análisis de sobrevida con el método de Kaplan-Meier y el test Log-rank para su comparación. Se consideró estadísticamente significativo un valor de p < 0,05. Resultados: 411 pacientes fueron operados por cáncer de recto, 143 pacientes recibieron neoadyuvancia, el 19% registró RPC. La SG del grupo con RPC fue 94% (IC 95%; 59,79-79,41%) mientras que la del grupo sin RPC fue 71% (IC 95%; 66,64-99,20%) (p = 0,018), la SLE en aquellos pacientes con RPC alcanzó un 100%, mientras que en aquellos sin RPC fue 74% (IC 95%; 64,08-81,28) (p = 0,008). Conclusiones: Los pacientes con RPC mostraron mejores resultados a largo plazo que aquellos sin RPC. La RPC podría indicar un perfil tumoral biológico favorable, con menos tendencia a la recurrencia y mejor supervivencia.

Background: One of the mainstays in the treatment of locally advanced rectal cancer is neoadjuvant chemoradiotherapy. Neoadjuvant therapy have demonstrated to decrease local recurrence, also generating tumor downstaging, even leading to a pathological complete response (PCR), the latter related to better overall survival (OS) and disease-free survival (SLE). Aim: To report the anatomo-pathological results of treatment with chemoradiotherapy in rectal cancer, analyzing the relationship with OS and SLE. Material and Method: Prospective cohort study. A database of colorectal surgeries from the Clinical Hospital of the University of Chile between the years 2004-2019, including patients with locally advanced low and middle rectal cancer, who received neoadjuvant and later surgery. Survival analysis was made with the Kaplan-Meier method and the Log-rank test for comparison. A value of p < 0.05 was considered statistically significant. Results: 411 patients underwent surgery for rectal cancer, 143 patients received neoadjuvant therapy, 19% registered PCR. The OS of the group with PCR was 94% (95% CI; 59.79-79.41%) while that of the group without PCR was 71% (95% CI; 66.64-99.20%) (p = 0.018), the SLE in those patients with PCR reached 100%, while in those without PCR it was 74% (95% CI; 64.08-81.28) (p = 0.008). Conclusions: Patients with PCR have better long-term results than those without PCR. PCR could indicate a favorable biological tumor profile, with less tendency to recurrence and improved survival.

Lymph Node Metastasis in Extraperitoneal Rectal Cancer After Neoadjuvant Therapy: An Unsolved Problem?

BACKGROUND/AIM: Thanks to the promising benefits obtained in terms of quality of life, there has been growing interest in organ-sparing approaches after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer, mainly represented by transanal local excision and watch-and-wait. The main mandatory criterion is complete lymph nodal response (pN0). However, considering the reduced specificity of current radiological means in identifying one-to-one correspondence between clinical and pathological staging, the problem of underestimating lymph nodal involvement remains unsolved. The aim of this study was to identify the true percentage of patients eligible for conservative surgery and possible predictive factors. PATIENTS AND METHODS: Data for 59 patients with rectal cancer treated with nCRT followed by total mesorectal excision were analyzed. Patients with metastatic tumors and tumors treated with up-front surgery were excluded. Our primary endpoint was the pathological lymph nodal response rate after neoadjuvant chemoradiotherapy. The secondary endpoint was to identify predictive factors for lymph nodal response. RESULTS: The percentage of patients with pN0 was 62.71%, while in 37.28%, an organ-sparing approach would have not been oncologically correct. Parameters associated with pN0 were lower tumor size (T0-T2) (p=0.013) and lower grading (

Particular aspects of treating rectal cancer: The watch and wait approach.

Background: Rectal cancer is one of the most common malignant pathologies worldwide. Currently, the standard treatment of this pathology consists of radio-chemotherapy followed by low anterior resection with total mesorectal excision or abdominoperineal proctectomy for medium/low rectal cancer. Objectives: In recent years, another treatment strategy has been proposed, stemming from the finding that up to 40% of patients receiving neoadjuvant treatment had a complete pathological response. This method, also referred to as the watch and wait approach, implies delaying surgery and following a rigorous protocol for patients who have developed a complete response to neoadjuvant treatment with a good oncologic outcome. The objective of this study was to highlight the merits of this approach in selected patients. Case Reports: In this study, we present two patients with low-rectal tumors who developed complete response post neoadjuvant therapy and for whom the watch and wait protocol has been applied over the past 4 years. Conclusion: Although the watch and wait protocol appears to be a feasible option in the management of patients with a complete clinical and pathological response post neoadjuvant therapy, more prospective studies and randomized trials comparing this approach with standard surgical treatment are required before establishing it as the standard of care for distal rectal cancer. Therefore, establishing universal criteria for the selection and assessment of the patients with a complete clinical response following neoadjuvant treatment is required.

Post-mastectomy radiation therapy in HER-2 positive breast cancer after primary systemic therapy: Pooled analysis of TRYPHAENA and NeoSphere trials.

PURPOSE: The role of post-mastectomy radiation therapy (PMRT) following primary systemic therapy (PST) in HER-2 positive breast cancer (Her2 + BC) remains poorly understood. The current study evaluates PMRT based on the pathological response to PST in Her2 + BC. METHODS AND MATERIALS: TRYPHAENA and NeoSphere are randomized phase II trials that investigated PST for Her2 + BC. Our study is a pooled analysis of both trials, including 312 node-positive patients treated with HER-2 targeted PST followed by mastectomy with or without PMRT. The primary endpoint is loco-regional recurrence-free survival (LRRFS). RESULTS: Our analysis included 172 (55%) patients who achieved complete nodal pathological response (ypN0) and 140 (45%) patients who did not. Patients with ypN0 had a 5-year LRRFS of 97% in both, the PMRT and no PMRT, groups (p = 0.94). Patients with ypN + had 5-year LRRFS of 89% in the PMRT group and 82% in the no PMRT group (p = 0.17). Patients with ypN1 (n = 62) disease who received PMRT (n = 40) had a 5-year LRRFS of 85% as compared to 89% in those who did not (n = 22); (p = 0.60). A significant LRRFS difference was noted in patients with ypN2-3 (n = 78) disease who received PMRT (n = 53) compared to those who did not (n = 25) (5-year LRRFS 92% vs. 75%; p = 0.019). On multivariate analysis, clinical nodal disease at diagnosis and ypN0 were significantly associated with loco-regional recurrence (LRR). CONCLUSIONS: Her2 + BC patients who achieve ypN0 after PST have excellent locoregional-control which supports de-escalation of PMRT. In contrast, patients with ypN2-3 disease derive significant benefit from PMRT. Clinical nodal stage at presentation and ypN0 status are significantly associated with LRR risk in Her2 + BC.

New insights into breast microcalcification for poor prognosis: NACT cohort and bone metastasis evaluation cohort.

OBJECTIVES: The study aimed to analyze the poor prognosis of microcalcification in breast cancer (BC), including the pathological complete response (pCR) to neoadjuvant chemotherapy (NACT) and the risk of bone metastases. MATERIALS AND METHODS: 313 breast cancer patients received NACT to evaluate pCR and 1182 patients from a multicenter database to assess bone metastases were retrospectively included. Two groups were divided according to the presence or absence of mammography microcalcification. Clinical data, image characteristics, neoadjuvant treatment response, bone involvement, and follow-up information were recorded. The pCR and bone metastases were compared between subgroups using the Mann-Whitney and χ2 tests and logistic regression, respectively. RESULTS: Mammographic microcalcification was associated with a lower pCR than uncalcified BC in the NACT cohort (20.6% vs 31.6%, P = 0.029). Univariate and multivariate analysis suggested that calcification was a risk factor for poor NACT response [OR = 1.780, 95%CI (1.065-2.974), P = 0.028], [OR = 2.352, 95%CI (1.186-4.667), P = 0.014]. Microcalcification was more likely to be necrosis on MRI than those without microcalcification (53.0% vs 31.7%, P < 0.001), multivariate analysis indicated that tumor necrosis was also a risk factor for poor NACT response [OR = 2.325, 95%CI (1.100-4.911), P = 0.027]. Age, menopausal status, breast density, mass, molecular, and pathology type were not significantly associated with non-pCR risk assessment. In a multicenter cohort of 1182 patients with pathologically confirmed BC, those with microcalcifications had a higher proportion of bone metastases compared to non-calcified BC (11.6% vs 4.9%, P < 0.001). Univariate and multivariate analysis showed that microcalcification was an independent risk factor for bone metastasis [OR = 2.550, 95%CI (1.620-4.012), P < 0.001], [OR = 2.268(1.263-4.071), P = 0.006)]. Osteolytic bone metastases predominated but there was no statistical difference between the two groups (78.9% vs 60.7%, P = 0.099). Calcified BC was mainly involved in axial bone, but was more likely to involve the whole-body bone than non-calcified BC (33.8% vs 10.7%, P = 0.021). CONCLUSION: This study provides important insights into the poor prognosis of microcalcification, not only in terms of poor response to NACT but also the risk factor of bone metastases.