Case report: Durable complete response of a mucosal melanoma of the rectum after neoadjuvant immunotherapy with ipilimumab plus nivolumab.

Melanoma causes the majority of skin cancer-related deaths. Despite novel therapy options, metastatic melanoma still has a poor prognosis. Immune checkpoint inhibition (ICI) therapy has been shown to prolong overall survival in patients with advanced melanoma, but mucosal melanomas respond less favorably compared to melanomas of cutaneous origin. We report on a patient with a mucosal melanoma of the rectum diagnosed in June 2020. Since a surgical intervention in order to achieve a tumor-free situation would have required an amputation of the rectum, a neo-adjuvant systemic immunotherapy with ipilimumab and nivolumab was initiated. As restaging and colonoscopy after four doses of this combination immunotherapy showed a partial response, the patient decided against the pre-planned surgery and a maintenance therapy with nivolumab was started. Repeated colonoscopy showed a complete response after four doses of nivolumab. After ongoing ICI therapy with nivolumab and no evidence of tumor relapse, immunotherapy was stopped in July 2022 after nearly 2 years of continuous treatment. The patient remained tumor-free during further follow-up. Neo-adjuvant immunotherapy is getting more explored in advanced melanoma. By administering ICI therapy before surgical resection of an essentially operable tumor, a stronger and more diverse immunological response is supposed to be achieved. Our reported case demonstrates that this approach could also be effective in mucosal melanoma despite of its generally lower response to immunotherapy.

Osteonecrosis of the jaw after radiation followed by bevacizumab.

Osteonecrosis of the jaw is a recognized complication associated with bevacizumab. Here, we present a patient with squamous cell carcinoma of the tonsil who experienced minimal skin fibrosis following intensity-modulated radiation therapy. Subsequently, the patient developed rectal adenocarcinoma and encountered osteonecrosis of the jaw after receiving two cycles of bevacizumab. Close monitoring, accompanied by thorough examination to detect early signs of osteonecrosis of the jaw, should be considered for patients who have undergone radiation therapy in the head and neck region and are receiving bevacizumab or other medications known to be associated with osteonecrosis of the jaw.

Penile-scrotal erythrodysesthesia among rectal cancer patients receiving fluoropyrimidine-based chemoradiation: a case report series.

BACKGROUND: Palmar-plantar erythrodysesthesia (PPE) is a slowly developing cutaneous reaction commonly experienced by patients treated with fluoropyrimidines. While erythrodysesthesia normally presents in a palmar-plantar distribution, it can also present with genital involvement, but this presentation is likely underreported and incorrectly attributed to an acute reaction from radiation therapy. This article aims to define erythrodysesthesia of the penis and scrotum as a rare but significant side effect of capecitabine. CASE PRESENTATION: We identified five cases of moderate to severe penis and scrotal erythrodysesthesia over a 2-year period at a large tertiary cancer center, representing an estimated incidence of 3.6% among male patients with rectal cancer who were treated with fluoropyrimidine-based chemoradiation within our institution. CONCLUSIONS: Improved understanding of erythrodysesthesia involving the penis and scrotum can facilitate early identification and treatment of symptoms, and possibly prevent the discontinuation or delay of cancer treatment in patients treated with capecitabine and similar drugs. These clinical advances would improve and prolong patient quality of life during cancer treatment and prevent complications that result in hospitalization.

Case report: Decreased hemoglobin and multiple organ failure caused by ceftizoxime-induced immune hemolytic anemia in a Chinese patient with malignant rectal cancer.

Background: Drug-induced immune hemolytic anemia (DIIHA) is a rare but serious condition, with an estimated incidence of one in 100,000 cases, associated with various antibiotics. This study reports on a case of ceftizoxime-induced hemolysis observed in a patient in China. Case description: A Chinese patient diagnosed with malignant rectal cancer underwent antimicrobial therapy after laparoscopic partial recto-sigmoid resection (L-Dixon). After receiving four doses of ceftizoxime, the patient developed symptoms including rash, itchy skin, and chest distress, followed by a rapid decline in hemoglobin levels, the presence of hemoglobin in the urine (hemoglobinuria), renal failure, and disseminated intravascular coagulation. Laboratory analysis revealed high-titer antibodies against ceftizoxime and red blood cells (RBCs) in the patient's serum, including immunoglobulin M (IgM) (1:128) antibodies and immunoglobulin G (IgG) (1:8) antibodies, with noted crossreactivity to ceftriaxone. Significant improvement in the patient's hemolytic symptoms was observed following immediate discontinuation of the drug, two plasma exchanges, and extensive RBC transfusion. Conclusion: This case, together with previous reports, underscores the importance of considering DIIHA in patients who exhibit unexplained decreases in hemoglobin levels following antibiotic therapy. A thorough examination of the patient's medical history can provide crucial insights for diagnosing DIIHA. The effective management of DIIHA includes immediate cessation of the implicated drug, plasma exchange, and transfusion support based on the identification of specific drug-dependent antibodies through serological testing.

Novel radiation and targeted therapy combinations for improving rectal cancer outcomes.

Neoadjuvant radiotherapy (RT) is commonly used as standard treatment for rectal cancer. However, response rates are variable and survival outcomes remain poor, highlighting the need to develop new therapeutic strategies. Research is focused on identifying novel methods for sensitising rectal tumours to RT to enhance responses and improve patient outcomes. This can be achieved through harnessing tumour promoting effects of radiation or preventing development of radio-resistance in cancer cells. Many of the approaches being investigated involve targeting the recently published new dimensions of cancer hallmarks. This review article will discuss key radiation and targeted therapy combination strategies being investigated in the rectal cancer setting, with a focus on exploitation of mechanisms which target the hallmarks of cancer.

Impact of Neoadjuvant Radiochemotherapy on Pathological Complete Response for Locally Advanced Rectal Cancer: A Mono Institutional Experience.

BACKGROUND/AIM: Neoadjuvant radiochemotherapy followed by surgery is a standard of care in locally advanced rectal cancer (LARC). Only a subgroup of patients can obtain a pathological complete response (pCR) and achieve good local control. However, the role of pCR on patient survival is debated. The aim of the study was to evaluate the impact of pCR on clinical outcomes and toxicities in LARC patients treated with dose intensification and concomitant capecitabine treatment in a neoadjuvant radiochemotherapy schedule. PATIENTS AND METHODS: This was a single Institution retrospective study including 178 patients. Mandard tumor regression grade (TRG) and pTNM staging system were used to classify pathological response and define pathological complete response (pCR). Patients were divided in: pCR (pT0N0) and Not-pCR (pT>0N>0), according to pTNM and in good responders (TRG1-2) and partial/not responders (TRG3-5), according to Mandard TRG. The Kaplan-Meier method was used to estimate OS, CSS, DFS and LC. RESULTS: A low severe toxicity rate was observed. Acute Grade 3 lower bowel toxicity and Grade 3 cutaneous toxicity were reported in 2 (1.1%) patients, respectively. Late Grade >3 lower bowel toxicity was reported in 6 patients (3%) and late Grade >3 cutaneous toxicity was registered in one patient. No other severe acute and late toxicities were reported. The 5- and 10-year OS, CSS, DFS and LC rates were 85% and 75%, 94% and 92%, 83% and 81%, 88% and 88%, respectively. We observed a pCR rate of 36% and a good responders rate of 62%, in our study population. Both groups showed better rates for each analyzed clinical outcome. CONCLUSION: Neoadjuvant radiochemotherapy with dose intensification in LARC patients resulted in favorable long-term oncological outcomes, pCR rate showed an optimal impact on OS and DFS with an acceptable toxicity.

The efficacy and safety of short-course radiotherapy followed by sequential chemotherapy and Cadonilimab for locally advanced rectal cancer: a protocol of a phase II study.

BACKGROUND: For patients with locally advanced rectal cancer (LARC), total neoadjuvant therapy (TNT), namely, intensifying preoperative treatment through the integration of radiotherapy and systemic chemotherapy before surgery, was commonly recommended as the standard treatment. However, the risk of distant metastasis at 3 years remained higher than 20%, and the complete response (CR) rate was less than 30%. Several clinical trials had suggested a higher complete response rate when combining single-agent immunotherapy with short-course radiotherapy (SCRT). The CheckMate 142 study had shown encouraging outcomes of dual immunotherapy and seemingly comparable toxicity for CRC compared with single-agent immunotherapy in historical results. Therefore, dual immunotherapy might be more feasible in conjunction with the TNT paradigm of SCRT. We performed a phase II study to investigate whether the addition of a dual immune checkpoint inhibitor bispecific antibody, Cadonilimab, to SCRT combined with chemotherapy might further increase the clinical benefit and prognosis for LARC patients. METHODS: This single-arm, multicenter, prospective, phase II study included patients with pathologically confirmed cT3-T4N0 or cT2-4N + rectal adenocarcinoma with an ECOG performance score of 0 or 1. Bispecific antibody immunotherapy was added to SCRT combined with chemotherapy. Patients enrolled would be treated with SCRT (25 Gy in five fractions over 1 week) for the pelvic cavity, followed by 4 cycles of CAPOX or 6 cycles of mFOLFOX and Cadonilimab. The primary endpoint was the CR rate, which was the ratio of the pathological CR rate plus the clinical CR rate. The secondary endpoints included local-regional control, distant metastasis, disease-free survival, overall survival, toxicity profile, quality of life and functional outcome of the rectum. To detect an increase in the complete remission rate from 21.8% to 40% with 80% power, 50 patients were needed. DISCUSSION: This study would provide evidence on the efficacy and safety of SCRT plus bispecific antibody immunotherapy combined with chemotherapy as neoadjuvant therapy for patients with LARC, which might be used as a candidate potential therapy in the future. TRIAL REGISTRATION: This phase II trial was prospectively registered at ClinicalTrials.gov, under the identifier NCT05794750.

[Exploration of the method and efficacy of treatments for intractable pelvic pain caused by rectal or bladder fistula].

Objective: To explore the causes and therapeutic effects of pelvic pain caused by rectal fistula or bladder fistula after comprehensive treatment of cervical cancer and rectal cancer (radiotherapy, surgery, chemotherapy, and other treatments). Methods: A retrospective analysis was conducted on the clinical and pathological data of patients with pelvic tumors admitted to the First People's Hospital of Yinchuan City, Ningxia and the Affiliated Cancer Hospital of Zhengzhou University from June 2016 to June 2022. The causes of persistent pelvic pain in patients after comprehensive treatment was investigated, and the corresponding therapeutic effects after clinical treatment was observed. Results: Thirty-two tumor patients experienced persistent pain after comprehensive treatment, including 22 cases of cervical cancer and 10 cases of rectal cancer. The preoperative pain of the entire group of patients was evaluated using the digital grading method, with a pain score of (7.88±1.31) points. Among the 32 patients, there were 16 cases of rectovaginal fistula or ileovaginal fistula, 9 cases of vesicovaginal fistula, 5 cases of rectoperineal fistula, and 2 cases of vesicovaginorectal fistula. Thirty-two patients were initially treated with medication to relieve pain, and according to the ruptured organs, a fistula was made to the corresponding proximal intestinal canal and renal pelvis to intercept the intestinal contents and urine. However, the pain did not significantly be improved. The pain score of treatment with the above methods for one week was (8.13±1.13) points, and there was no statistically significant difference compared to preoperative treatment (P=0.417). In the later stage, based on a comprehensive evaluation of whether the tumor had recurred, the value of organ preservation, the benefits of surgery, the balance between survival time and improving quality of life, pathological organ resection or repair was performed. The surgical methods included repair of leaks, local debridement combined with irrigation of proximal intestinal fluid, distal closure of the sigmoid colon combined with proximal ostomy, posterior pelvic organ resection, anterior pelvic organ resection, and total pelvic organ resection. One week after surgery, the patients' pain completely relieved or disappeared, with the pain score of (1.72±1.37) points, which was significantly divergent from the preoperative and initial surgical treatments (P＜0.001). Conclusions: Palliative pyelostomy and proximal enterostomy cannot effectively alleviate persistent pelvic floor pain. The fundamental way to alleviate pain is complete blocking of the inflammatory erosion of the intestinal fluid and urine.

[A Case of Pathologically Complete Response after Preoperative Chemotherapy in a Locally Advanced Rectal Cancer].

The case is a 78-year-old male. The chief complaint was melena and weight loss. After careful examination, the patient was diagnosed with advanced rectal cancer, and 3 courses of capecitabine plus oxaliplatin therapy were performed as preoperative chemotherapy. He underwent robot-assisted laparoscopic rectal resection, D3 lymphadenectomy, lateral lymphadenectomy, and temporary colostomy, and was discharged on hospital day 15. Postoperative pathological diagnosis showed only ulcerative lesions in the rectum, and malignant cells could not be confirmed. After postoperative adjuvant chemotherapy, the patient is alive without recurrence on an outpatient basis. There are many reports that it is slightly lower than radiotherapy. Therefore, it is important to select a more appropriate preoperative treatment, and the concentration of future cases is recognized.

Efficacy and safety of PD-1 blockade plus long-course chemoradiotherapy in locally advanced rectal cancer (NECTAR): a multi-center phase 2 study.

Adding PD-1 blockade in the neoadjuvant regimens for locally advanced rectal cancer (LARC) patients with microsatellite stable (MSS) / mismatch repair-proficient (pMMR) tumors is an attractive, but debatable strategy. This phase 2, multicenter, prospective, single-arm study enrolled patients from 6 centers from June 2021 to November 2022. Locally advanced rectal cancer (LARC, cT3-4aN0M0 and cT1-4aN1-2M0) patients aged ≥18 years with the distance from distal border of tumor to anal verge ≤10 cm (identified by Magnetic Resonance Imaging) were qualified for inclusion. The patients received long-course radiotherapy (50 Gy/25 fractions, 2 Gy/fraction, 5 days/week) and three 21-day cycles capecitabine (850-1000 mg/m2, bid, po, day1-14) and three 21-day cycles tislelizumab (200 mg, iv.gtt, day8) as neoadjuvant. Total mesorectal excision (TME) was 6-12 weeks after the end of radiotherapy to achieve radical resection. A total of 50 patients were enrolled in this study. The pathological complete response rate was 40.0% [20/50, 95% confidence interval (CI): 27.61-53.82%], while 15 (30.0%, 95% CI: 19.1-43.75%), 9 (18.0%, 95% CI: 9.77-30.8%), 2 (4.0%, 95% CI: 1.10-13.46%) patients respectively achieved grade 1, 2, and 3 tumor regression. Treatment-related adverse events (TRAEs) occurred in 28 (56.0%) LARC patients, including 26(52.0%) with grade I-II and 2 (4.0%) with grade III (1 with grade 3 immune-related colitis and 1 with grade 3 rash). PD-1 blockade plus long-course chemoradiotherapy (CRT) showed promising therapeutic effects according to pathological complete response rate and is well-tolerated in LARC patients. A larger randomized controlled study is desired to further validate the above findings.

Clinical Outcomes of Ileostomy Closure during versus after Adjuvant Chemotherapy in Patients with Rectal Cancer.

Background: Protective ileostomy can effectively prevent severe anastomotic leakage after rectal cancer surgery; however, the optimal timing for ileostomy closure during adjuvant chemotherapy remains unclear. This study aimed to explore the safety and long-term outcomes of early ileostomy closure during adjuvant chemotherapy. Method: Patients who underwent laparoscopic rectal cancer surgery combined with protective ileostomy and adjuvant chemotherapy between April 2017 and April 2021 were retrospectively evaluated. Patients were divided into an early closure group during chemotherapy (group A) and a late closure group after chemotherapy (group B). Results: A total of 215 patients were included in this study, with 115 in group A and 100 in group B. There were no significant differences in demographic and clinical characteristics between the two groups. In group A, durations of stoma status (p < 0.001) and low anterior resection syndrome (LARS) (p < 0.001) were shorter, and rectal stenosis (p=0.036) and stoma-related complications (p=0.007), especially stoma stenosis (p=0.041), were less common. However, compliance with chemotherapy was worse (p=0.009). There were no significant differences in operative time, postoperative hospital stay, postoperative complications, incidence and severity of LARS, disease-free survival, or overall survival between groups. Conclusion: Early ileostomy closure can effectively reduce the duration of stoma status, duration of LARS, rectal stenosis, and stoma-related complications while not affecting surgical complications and oncological outcomes. Ileostomy closure should not be delayed because of adjuvant chemotherapy. However, follow-up should be strengthened to increase compliance and integrity with chemotherapy.

ST6GAL1 is associated with poor response to chemoradiation in rectal cancer.

INTRODUCTION: Colorectal cancer is the third most common cause of cancer death. Rectal cancer makes up a third of all colorectal cases. Treatment for locally advanced rectal cancer includes chemoradiation followed by surgery. We have previously identified ST6GAL1 as a cause of resistance to chemoradiation in vitro and hypothesized that it would be correlated with poor response in human derived models and human tissues. METHODS: Five organoid models were created from primary human rectal cancers and ST6GAL1 was knocked down via lentivirus transduction in one model. ST6GAL1 and Cleaved Caspase-3 (CC3) were assessed after chemoradiation via immunostaining. A tissue microarray (TMA) was created from twenty-six patients who underwent chemoradiation and had pre- and post-treatment specimens of rectal adenocarcinoma available at our institution. Immunohistochemistry was performed for ST6GAL1 and percent positive cancer cell staining was assessed and correlation with pathological grade of response was measured. RESULTS: Organoid models were treated with chemoradiation and both ST6GAL1 mRNA and protein significantly increased after treatment. The organoid model targeted with ST6GAL1 knockdown was found to have increased CC3 after treatment. In the tissue microarray, 42 percent of patient samples had an increase in percent tumor cell staining for ST6GAL1 after treatment. Post-treatment percent staining was associated with a worse grade of treatment response (p = 0.01) and increased staining post-treatment compared to pre-treatment was also associated with a worse response (p = 0.01). CONCLUSION: ST6GAL1 is associated with resistance to treatment in human rectal cancer and knockdown in an organoid model abrogated resistance to apoptosis caused by chemoradiation.

Dynamic ctDNA-based analysis of drug-resistant gene alterations at RAS/BRAF wild-type metastatic colorectal cancer patients after cetuximab plus chemotherapy as the first-line treatment.

BACKGROUND: The purpose of this study was to explore the dynamic changes of genomic mutations and their correlations with the efficacy in metastatic colorectal cancer (mCRC) patients treated with cetuximab plus mFOLFOX as the first-line treatment. METHODS: We included mCRC patients from January 2018 to October 2020 as a studied cohort which were treated with cetuximab plus mFOLFOX as first line therapy. Blood samples were collected for circulating tumor DNA (ctDNA) test at three timepoints: before the first-line therapy(baseline), at the time of first-line progression and at the time of second-line progression. Progression-free survival was considered as the primary endpoint while objective response rate and overall survival were determined as the secondary endpoints. RESULTS: Totally 39 patients received first-line treatment, of which 25 patients entered the second-line treatment, while 10 patients entered the third-line treatment. The median follow-up time was 16.4 months (95 %CI, 14.8-19.3). Along the treatment from first-line progress disease (PD) to second-line PD, proportions of TP53 (12/18, 67 %), APC (10/18, 56 %), FBXW7 (3/18, 17 %), and AMER1 (2/18, 11 %) were gradually increased according to results of single nucleotide variation (SNV). CONCLUSIONS: Resistant gene mutations caused by anti-EGFR drugs in RAS/BRAF wild-type mCRC patients can be observed by dynamic ctDNA analysis. TP53 and AMER1 mutations, tumor mutational burden (TMB) levels, and TP53/AMER1 co-mutation may predict the efficacy of the first-line cetuximab-contained treatment. Situations of genetic mutations were differentiated from first-line PD to second-line PD, which indicated that mutation detection may contribute to predict prognosis of mCRC patients.

Modified FOLFIRINOX (mFOLFIRINOX) as neoadjuvant therapy and 'salvage' in patients with high risk locally advanced rectal cancers - tolerance and early outcomes.

BACKGROUND: There is limited data with regard to the use of modified 5-fluoroural-leucovorin-irinotecan-oxaliplatin (mFOLFIRINOX) in terms of tolerance and enabling total mesorectal excision (TME) of locally advanced rectal adenocarcinomas (LARC) with high-risk characteristics (T4b status, signet ring histology etc) post standard neoadjuvant long course chemoradiation (NACTRT) or short course radiation (SCRT) and chemotherapy. MATERIALS AND METHODS: Patients with LARC from January 2018 to December 2020 receiving mFOLFIRINOX post NACTRT/SCRT to facilitate TME were evaluated. The primary endpoint was assessment of grade 3 and grade 4 treatment related toxicity and TME rates. Event free survival (EFS), where event was defined as disease progression or recurrence post resection after mFOLFIRINOX, was calculated by Kaplan Meier method. RESULTS: Forty-seven patients were evaluated with a median age of 33 years (Range:18-59), 45% T4b status, 96% radiological circumferential margin (CRM) involved (79% CRM positive post NACTRT/SCRT), 43% extramural venous invasion (n=33) and 36% signet ring histology. 62% had received prior NACTRT and 38% had received SCRT with chemotherapy before receiving mFOLFIRINOX. The most common grade 3 and grade 4 treatment related side effects included diarrhoea (7%), anaemia (4%) and infections (4%). Intended duration of mFOLFIRINOX or beyond was completed in 94% of patients. 60% of patients underwent curative local resection with R0 resection rates of 100% (n=28) and pathological complete response rates of 21%. The most common surgeries done were exenterations and abdominoperineal in 22% and 17% patients respectively. With a median follow up of 19 months, 24 patients had recurred or progressed for a median EFS of 20 months [95% confidence interval (CI): 15-24]. CONCLUSIONS: Locally advanced rectal cancers with high-risk characteristics are a niche group of cancers with less-than-optimal outcomes post standard neoadjuvant strategies. mFOLFIRINOX appears to be well tolerated and enables TME in a significant proportion of these patients.

Twelve-month progression-free survival with sotorasib and panitumumab in KRAS G12C mutant metastatic colorectal cancer.

Colorectal cancer (CRC) ranks third in global cancer prevalence, with 40% presenting as metastatic colorectal cancer (mCRC). KRAS mutations in mCRC patients confer resistance to anti-EGFR treatments. Promising inhibitors such as sotorasib and adagrasib targeting KRASG12C mutations have demonstrated efficacy. Herein, we present a heavily pretreated mCRC case with a progression-free survival of 12 months with sotorasib and panitumumab. In 2017, a 27-year-old male presented with abdominal pain and received a diagnosis of stage IIIC KRAS G12C mutant CRC. Following surgery and adjuvant chemotherapy, he developed metastases in the liver and lungs in 2020. Treatment with FOLFIRINOX and bevacizumab, and later FOLFIRI and bevacizumab, with surgeries and local interventions resulted in partial responses. Upon disease progression, sotorasib and panitumumab were initiated, achieving a complete metabolic response. After 12 months of progression-free survival, oligoprogressive liver lesions were surgically resected. This case highlights the remarkable outcome of a heavily treated KRAS G12C mutant mCRC patient. The combination of sotorasib and panitumumab, along with multidisciplinary approaches including surgery and local interventions, played an important role in our patient's survival.

Somatostatin receptor 2 (SSTR2) expression is associated with better clinical outcome and prognosis in rectal neuroendocrine tumors.

Somatostatin analogues have recently been used as therapeutic targets for metastatic or surgically unresectable gastroenteropancreatic (GEP) neuroendocrine tumors (NETs), and associated somatostatin receptor (SSTR) expression has been well demonstrated in most GEP NETs, with the exception of rectal NETs. SSTR2 immunohistochemical expressions were evaluated in 350 surgically or endoscopically resected rectal NETs and compared to clinicopathologic factors. SSTR2 expression was observed in 234 (66.9%) rectal NET cases and associated tumors with smaller size (p = 0.001), low pT classification (p = 0.030), low AJCC tumor stage (p = 0.012), and absence of chromogranin expression (p = 0.009). Patients with rectal NET and SSTR2 expression had significantly better overall survival than those without SSTR2 expression both by univariable (p = 0.006) and multivariable (p = 0.014) analyses. In summary, approximately two-thirds of rectal NETs expressed SSTR2. SSTR2 expression was significantly associated with favorable behavior and good overall survival in patients with rectal NETs. Furthermore, SSTR2 expression can be used as prognostic factors. When metastatic disease occurs, SSTR2 expression can be used a possible target for somatostatin analogues.

Magnetic resonance imaging for assessment of rectal cancer nodes after chemoradiotherapy: A single center experience.

BACKGROUND: Accurate nodal restaging is becoming clinically more important in patients with locally advanced rectal cancer (LARC) with the emergence of organ-preserving treatment after a good response to neoadjuvant chemoradiotherapy (nCRT). PURPOSE: To evaluate the accuracy of MRI in identifying negative N status (ypN0 patients) in LARC after nCRT. MATERIAL AND METHODS: 191 patients with LARC underwent MRI before and 6-8 weeks after nCRT and subsequent total mesorectal excision. Short-axis diameter of mesorectal lymph nodes was evaluated on the high resolution T2-weighted images to compare MRI restaging with histopathology.. RESULTS: 146 and 45 patients had a negative N status (ypN0) and positive N status (ypN + ), respectively. On restaging MRI, the 70 % reduction in size of the largest node was associated with an area under the curve (AUC) of 0.818 to predict ypN0 stage, with a sensitivity of 93.3 % and a negative predictive value (NPV) of 95.4 %. No nodes were observed in 38 pts (37 pts ypN0 and 1 patient ypN + ), with sensitivity and NPV of nodes disappearance for ypN0 stage of 93.3 % and 92.5 % respectively. A 2.2 mm cut-off in short-axis diameter was associated with an AUC of 0.83 for the prediction of ypN0 nodal stage, with sensitivity and NPV of 79,5% and 91.1 % respectively. CONCLUSION: A reduction in size of 70 % of the largest limph-node on MRI at rectal cancer restaging has high sensitivity and NPV for prediction of ypN0 stage after nCRT. The high NPV of node disappearance and of a ≤ 2.2 mm short-axis diameter is confirmed.

A phase II study of guadecitabine combined with irinotecan vs regorafenib or TAS-102 in irinotecan-refractory metastatic colorectal cancer patients.

DNA methyltransferase inhibitors (DNMTi) have demonstrated benefit in reversing resistance to systemic therapies for several cancer types. In a phase II trial of guadecitabine and irinotecan compared to regorafenib or TAS-102 in pts with advanced mCRC refractory to irinotecan. Patients with mCRC refractory to irinotecan were randomized 2:1 to guadecitabine and irinotecan (Arm A) vs standard of care regorafenib or TAS-102 (Arm B) on a 28-day cycle. Between January 15, 2016 and October 24, 2018, 104 pts were randomized at four international sites, with 96 pts undergoing treatment, 62 in Arm A and 34 in Arm B. Median overall survival was 7.15 months for Arm A and 7.66 months for Arm B (HR 0.93, 95% CI: 0.58-1.47, P = .75). The Kaplan-Meier rates of progression free survival at 4 months were 32% in Arm A and 26% in Arm B. Common ≥Grade 3 treatment related adverse events in Arm A were neutropenia (42%), anemia (18%), diarrhea (11%), compared to Arm B pts with neutropenia (12%), anemia (12%). Guadecitabine and irinotecan had similar OS compared to standard of care TAS-102 or regorafenib, with evidence of target modulation. Clinical trial information: NCT01896856.

Genomic Characterization and Clinical Outcomes of Patients with Peritoneal Metastases from the AACR GENIE Biopharma Collaborative Colorectal Cancer Registry.

Peritoneal metastases (PM) are common in metastatic colorectal cancer (mCRC). We aimed to characterize patients with mCRC and PM from a clinical and molecular perspective using the American Association of Cancer Research Genomics Evidence Neoplasia Information Exchange (GENIE) Biopharma Collaborative (BPC) registry. Patients' tumor samples underwent targeted next-generation sequencing. Clinical characteristics and treatment outcomes were collected retrospectively. Overall survival (OS) from advanced disease and progression-free survival (PFS) from start of cancer-directed drug regimen were estimated and adjusted for the left truncation bias. A total of 1,281 patients were analyzed, 244 (19%) had PM at time of advanced disease. PM were associated with female sex [OR: 1.67; 95% confidence interval (CI): 1.11-2.54; P = 0.014] and higher histologic grade (OR: 1.72; 95% CI: 1.08-2.71; P = 0.022), while rectal primary tumors were less frequent in patients with PM (OR: 0.51; 95% CI: 0.29-0.88; P < 0.001). APC occurred less frequently in patients with PM (N = 151, 64% vs. N = 788, 79%) while MED12 alterations occurred more frequently in patients with PM (N = 20, 10% vs. N = 32, 4%); differences in MED12 were not significant when restricting to oncogenic and likely oncogenic variants according to OncoKB. Patients with PM had worse OS (HR: 1.45; 95% CI: 1.16-1.81) after adjustment for independently significant clinical and genomic predictors. PFS from initiation of first-line treatment did not differ by presence of PM. In conclusion, PM were more frequent in females and right-sided primary tumors. Differences in frequencies of MED12 and APC alterations were identified between patients with and without PM. PM were associated with shorter OS but not with PFS from first-line treatment. SIGNIFICANCE: Utilizing the GENIE BPC registry, this study found that PM in patients with colorectal cancer occur more frequently in females and right-sided primary tumors and are associated with worse OS. In addition, we found a lower frequency of APC alterations and a higher frequency in MED12 alterations in patients with PM.