Combination therapy with immune check point inhibitors and acute kidney injury.

BACKGROUND: Immune checkpoint inhibitors have revolutionized the treatment of metastatic renal cell carcinoma and malignant melanoma but are also associated with a risk of severe side effects. Nephrotoxicity is an immune checkpoint inhibitor-related adverse effect, but acute kidney injury (AKI) can also be caused by other more common conditions. This study aimed to describe the incidence and causes of AKI in patients treated with combination therapy of immune checkpoint inhibitors. MATERIAL AND METHODS: This retrospective cohort study included 200 patients receiving ipilimumab and nivolumab for either metastatic renal cell carcinoma or malignant melanoma at the Department of Oncology at Copenhagen University Hospital, Herlev between 1 January 2019 and 31 December 2020. The incidence and cause of AKI within 6 months after treatment was determined. RESULTS: In the 96 patients treated for malignant melanoma 15 patients (16%) had an episode of AKI. Two of these patients had potential immune checkpoint inhibitor-related AKI both of which received treatment with a proton pump inhibitor (PPI). Of the 104 included patients with metastatic renal cell carcinoma 26 patients (25%) developed AKI. Five of these patients had potential immune checkpoint inhibitor-related AKI. Treatment with PPI before the development of AKI occurred in 4 out of these 5 patients. CONCLUSION: Patients receiving combination therapy with checkpoint inhibitors are at high risk of AKI, but different causes of AKI should always be considered. Use of PPI concurrently with ICIs is likely to increase the risk of AKI.

Individualizing the Oncological Treatment of Patients With Metastatic Non-Clear Cell Renal Cell Carcinoma by Using Gene Sequencing and Patient-Reported Outcomes: Protocol for the INDIGO Study.

BACKGROUND: No phase 3 studies have yet been conducted for patients with non-clear cell (CC) renal cell carcinoma (RCC) exclusively due to the rare occurrence of the disease and the heterogenicity in tumor morphology. Consequently, there is no evidence of the optimal treatment, and new approaches are needed. One approach is individualizing treatment based on the gene sequencing of tumor tissue. Additionally, recent studies involving the patient-reported outcomes (PROs) of patients treated for metastatic cancer have shown significant benefits for quality of life, median overall survival, and overall survival. The use of gene sequencing and PROs can be of great importance to patients with rare cancer types, including patients with non-CC RCC, and should be investigated in clinical trials, especially for cases where evidence based on phase 3 studies is difficult to obtain. OBJECTIVE: We describe the INDIGO study, in which patients, based on gene analyses, will be allocated into 4 treatment arms containing 14 treatments and use electronic PROs. We aim to improve the treatment of patients with non-CC RCC. The end points in the study will be the overall response rate (complete and partial) in the total patient population, which will be based on the RECIST (Response Evaluation Criteria in Solid Tumors) version 1.1 criteria, and the time to treatment failure. METHODS: INDIGO is a prospective phase 2 trial, and 30 patients will be enrolled. The patients will receive systemic treatment based on genetic analyses of their tumor tissue. All patients will receive electronic questionnaires in a dedicated app-a questionnaire regarding symptoms and side effects and another regarding health-related quality of life. Depending on the treatment regimen, the patients will be seen by a medical doctor every third, fourth, or sixth week, and the effect of the systemic treatment will be evaluated every 6 weeks via a computed tomography scan. The study has been approved by the Danish Medicines Agency and the National Committee on Health Research Ethics (approval number: H-19041833), complies with good clinical practice guidelines, follows the General Data Protection Regulation, and is registered at the Capital Region of Denmark. RESULTS: Recruitment started in March 2020, and at the time of submitting this paper (June 2022), a total of 9 patients have been enrolled. CONCLUSIONS: We aim to explore methods for improving the treatment outcomes of patients with non-CC RCC, and the INDIGO study will contribute further data on personalized medicine for rare types of RCC and provide new knowledge on the active use of electronic PROs. TRIAL REGISTRATION: ClinicalTrials.gov NCT04644432, https://clinicaltrials.gov/ct2/show/NCT04644432 ; European Union Drug Regulating Authorities Clinical Trials Database 2019-001316-38, https://tinyurl.com/2p8mb4aw. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/36632.

ABCG2 Protein Levels and Association to Response to First-Line Irinotecan-Based Therapy for Patients with Metastatic Colorectal Cancer.

In this study we investigated the use of cancer cell protein expression of ABCG2 to predict efficacy of systemic first-line irinotecan containing therapy in patients with metastatic colorectal cancer (mCRC). From a Danish national cohort, we identified 119 mCRC patients treated with irinotecan containing therapy in first-line setting. Among these, 108 were eligible for analyses. Immunohistochemistry (IHC) analyses were performed on the primary tumor tissue in order to classify samples as high or low presence of ABCG2 protein. Data were then associated with patient outcome (objective response (OR), progression free survival (PFS) and overall survival (OS)). ABCG2 protein expression in the basolateral membrane was high (score 3+) in 33% of the patients. Exploratory analyses revealed a significant interaction between ABCG2 score, adjuvant treatment and OR (p = 0.041) in the 101 patients with evaluable disease. Patients with low ABCG2 (score 0-2) and no prior adjuvant therapy had a significantly higher odds ratio of 5.6 (Confidence Interval (CI) 1.68-18.7; p = 0.005) for obtaining OR. In contrast, no significant associations between ABCG2 expression and PFS or OS were found. These results suggest that measurement of the ABCG2 drug efflux pump might be used to select patients with mCRC for irinotecan treatment. However, additional studies are warranted before conclusions regarding a clinical use can be made. Moreover, patients with high ABCG2 immunoreactivity could be candidates for specific ABCG2 inhibition treatment in combination with irinotecan.

Associations between primary tumor RAS, BRAF and PIK3CA mutation status and metastatic site in patients with chemo-resistant metastatic colorectal cancer.

BACKGROUND: Several studies have investigated correlations between metastatic pattern and mutation status in patients with colorectal cancer (CRC). However, most of the studies were small and heterogeneously designed and further research is needed to confirm previous results. In this study, we investigated the association between RAS (KRAS or NRAS), BRAF, PIK3CA mutations and metastatic pattern in patients with metastatic (m) CRC. MATERIAL AND METHODS: This study reviewed Danish biobank and database of patients with mCRC who received cetuximab and irinotecan, independent of RAS mutation status, after fluoropyrimidine, oxaliplatin and irinotecan treatment failure. The database contained information regarding tumor mutation status of KRAS, NRAS, BRAF and PIK3CA genes. RESULTS: Totally, 448 patients were included. On multivariate analyses, RAS mutations were significantly associated with increased odds of having lung metastases at diagnosis of mCRC (odds ratio (OR) = 2.04; 95% confidence interval (CI) = 1.32-3.17), and PIK3CA mutations with decreased odds of peritoneal metastases at diagnosis of mCRC (OR = 0.10; 95%CI = 0.01-0.79). On multivariate analyses of the hazard of developing metastases at any time during follow-up, RAS mutations were significantly associated with increased hazard of lung (hazard ratio (HR) = 1.34; 95%CI = 1.04-1.72) and ovarian metastases (HR = 3.12; 95%CI = 1.05-9.24), BRAF V600E mutation was associated with increased hazard of skin metastases (HR = 6.82; 95%CI = 1.86-25.02) and PIK3CA mutations with decreased hazard of peritoneal metastases (HR = 0.31; 95%CI = 0.11-0.86). CONCLUSIONS: This study indicated that in patients with mCRC, RAS mutations are associated with increased risk of lung and ovary metastases. BRAF V600E is associated with increased risk of skin metastases, and PIK3CA mutation with decreased risk of peritoneal metastases.

Implications of ABCG2 Expression on Irinotecan Treatment of Colorectal Cancer Patients: A Review.

BACKGROUND: One of the main chemotherapeutic drugs used on a routine basis in patients with metastatic colorectal cancer ((m)CRC) is the topoisomerase-1 inhibitor, irinotecan. However, its usefulness is limited by the pre-existing or inevitable development of resistance. The ATP-binding cassette (ABC) transporter ABCG2/breast cancer resistance protein (BRCP) through its function in xenobiotic clearance might play an important role in irinotecan resistance. With a goal to evaluate the clinical significance of ABCG2 measurements, we here review the current literature on ABCG2 in relation to irinotecan treatment in CRC patients. RESULTS: Few studies have evaluated the association between ABCG2 gene or protein expression and prognosis in CRC patients. Discordant results were reported. The discrepancies might be explained by the use of different criteria for interpretation of results in the immunohistochemistry studies. Only one large study evaluated the ABCG2 protein expression and efficacy of irinotecan in mCRC (CAIRO study, n = 566). This study failed to demonstrate any correlation between ABCG2 protein expression in the primary tumor and response to irinotecan-based treatment. We recently raised questions on how to evaluate ABCG2 immunoreactivity patterns, and the results in the CAIRO study might be influenced by using a different scoring protocol than the one proposed by us. In contrast, our recent exploratory study of ABCG2 mRNA expression in 580 patients with stage III primary CRC (subgroup from the randomized PETACC-3 study) indicated that high ABCG2 tumor tissue mRNA expression might be predictive for lack of efficacy of irinotecan. CONCLUSION: The biological role of ABCG2 in predicting clinical irinotecan sensitivity/resistance in CRC is uncertain. In particular, the significance of ABCG2 cellular localization needs to be established. Data concerning ABCG2 mRNA expression and prediction of adjuvant irinotecan efficacy are still sparse and need to be confirmed.

Risk factors for brain metastases in patients with metastatic colorectal cancer.

BACKGROUND: Brain metastases (BM) from colorectal cancer (CRC) are rare, but the incidence is suspected to rise as treatment of metastatic (m) CRC improves. The aim of this study was to identify possible biological and clinical characteristics at initial presentation of mCRC that could predict later risk of developing BM. Furthermore, we wished to estimate the incidence of BM in long-term surviving patients. MATERIAL AND METHODS: We conducted a retrospective study on a Danish multicenter cohort of patients with mCRC who received cetuximab and irinotecan (CetIri) as third-line treatment. All patients had previously progression on 5-FU, irinotecan and oxaliplatin containing regimens and received CetIri treatment independent of RAS mutations status. We subsequently performed KRAS, NRAS, BRAF, PIK3CA, PTEN, ERBB2 and EGFR sequencing of DNA extracted from primary tumor tissue. RESULTS: Totally, 480 patients were included in our study. BM were diagnosed in 42 [8.8%; 95% confidence interval (CI) 6.4-11.6%] patients. Patients with BM had a significantly longer survival from mCRC diagnosis than non-BM patients (median = 32 versus 28 months, p = 0.001). On univariate cox regression analysis, the risk of developing BM was significantly increased in patients with rectal cancer (HR = 3.9; 95% CI = 1.2-13.3), metachronous metastatic disease (HR = 2.3; 95% CI = 1.2-4.4) and lung metastases (HR = 4.2; 95% CI = 2.2-7.9). On multivariate cox regression analysis only lung metastases were significantly associated BM (HR = 3.5; 95% CI = 1.8-6.8). None of the investigated mutations were associated with BM. CONCLUSION: The incidence of BM was 8.8% in patients with mCRC who received third-line therapy. The most important risk factor for developing BM was lung metastases. Furthermore, rectal cancer, metachronous metastatic disease and long survival were linked to BM development.

Topoisomerase I copy number alterations as biomarker for irinotecan efficacy in metastatic colorectal cancer.

BACKGROUND: No biomarker exists to guide the optimal choice of chemotherapy for patients with metastatic colorectal cancer. We examined the copy numbers (CN) of topoisomerase I (TOP1) as well as the ratios of TOP1/CEN-20 and TOP1/CEN-2 as biomarkers for irinotecan efficacy in patients with metastatic colorectal cancer. METHODS: From a national cohort, we identified 163 patients treated every third week with irinotecan 350 mg/m2 as second-line therapy. Among these 108 were eligible for analyses and thus entered the study. Primary tumors samples were collected and tissue microarray (TMA) blocks were produced. FISH analysis was performed using two probe-mixes: TOP1/CEN-20 and TOP1/CEN-2. Only samples harboring all three signals (TOP1, CEN-20 and CEN-2) using FISH were included in the analyses. RESULTS: In the TOP1/CEN-20 probe-mix the median TOP1- and CEN-20 CN were 4.46 (range: 1.5-9.5) and 2.00 (range: 0.55-4.55), respectively. The median TOP1- and CEN-2 CN in the TOP1/CEN-2 probe-mix, were 4.57 (range: 1.82-10.43) and 1.98 (range: 1.22-6.14), respectively. The median TOP1/CEN-20 ratio and TOP1/CEN-2 ratio were 1.25 (range: 0.92-2.90) and 2.05 (range: 1.00-6.00), respectively. None of the markers TOP1 CN, TOP1/CEN-20-ratio or TOP1/CEN-2-ratio were associated with progression free survival, overall survival or baseline characteristics. Yet, we observed a borderline association for a stepwise increase of the TOP1 CN in relation to objective response as hazard ratio were 1.35 (95% CI 0.96-1.90; p = 0.081). CONCLUSIONS: We verified a borderline significant association between increasing TOP1 CN and objective response as previously reported. Applying the probes representing CEN-20 and CEN-2, in order to investigate the ratios of TOP1/CEN-20 and TOP1/CEN-2 provided no further information in search of a biomarker driven patient stratification. Other biomarkers to be paired with TOP1 CN are therefore highly warranted.

Antibody validation and scoring guidelines for ABCG2 immunohistochemical staining in formalin-fixed paraffin-embedded colon cancer tissue.

Overexpression of the ATP-dependent drug efflux pump ABCG2 is a major molecular mechanism of multidrug resistance in cancer and might be a predictive biomarker for drug response. Contradictory results have been reported for immunohistochemical studies of ABCG2 protein expression in colorectal cancer (CRC), probably because of the use of different antibodies and scoring approaches. In this study, we systematically studied six commercially available anti-ABCG2 antibodies, using cell lines with up-regulation of ABCG2, and selected one antibody for validation in CRC tissue. Furthermore, we established scoring guidelines for ABCG2 expression based on the clinically used guidelines for HER2 immunohistochemistry assessment in gastric cancer. The guidelines provide a semi-quantitative measure of the basolateral membrane staining of ABCG2 and disregard the apical membrane staining and the cytoplasmic signal. Intra-tumor heterogeneity in ABCG2 immunoreactivity was observed; however, statistical analyses of tissue microarrays (TMAs) and the corresponding whole sections from primary tumors of 57 metastatic CRC patients revealed a strong positive correlation between maximum TMA scores and whole sections, especially when more than one core was used. In conclusion, here, we provide validated results to guide future studies on the associations between ABCG2 immunoreactivity in tumor cells and the benefits of chemotherapeutic treatment in patients with CRC.

Systematic review: brain metastases from colorectal cancer--Incidence and patient characteristics.

BACKGROUND: Brain metastases (BM) from colorectal cancer (CRC) are a rare event. However, the implications for affected patients are severe, and the incidence has been reported to be increasing. For clinicians, knowledge about the characteristics associated with BM is important and could lead to earlier diagnosis and improved survival. METHOD: In this paper, we describe the incidence as well as characteristics associated with BM based on a systematic review of the current literature, following the PRISMA guidelines. RESULTS: We show that the incidence of BM in CRC patients ranges from 0.6 to 3.2%. BM are a late stage phenomenon, and young age, rectal primary and lung metastases are associated with increased risk of developing BM. Molecular markers such as KRAS, BRAF, NRAS mutation as well as an increase in CEA and CA19.9 levels are suggested predictors of brain involvement. However, only KRAS mutations are reasonably well investigated and associated with an increased risk of BM. CONCLUSION: The incidence of BM from CRC is 0.6 to 3.2% and did not seem to increase over time. Development of BM is associated with young age, lung metastases, rectal primary and KRAS mutation. Increased awareness of brain involvement in patients with these characteristics is necessary.

A systematic review of salvage therapy to patients with metastatic colorectal cancer previously treated with fluorouracil, oxaliplatin and irinotecan +/- targeted therapy.

UNLABELLED: Oxaliplatin, irinotecan and 5-fluorouracil in combination with or without targeted therapies are well-documented treatment options for first- and second-line treatments of metastatic colorectal cancer. However, there are much less data on the beneficial effect on systemic therapy in the third-line setting. We therefore performed a systematic review of the current literature on third or later lines of treatment to patients with metastatic colorectal cancer after the use of approved drugs or combinations. METHODS: A computer-based literature search was carried out using Pubmed and data reported at international meetings. Original studies reporting ≥15 patients who had previously received 5-fluorouracil, oxaliplatin and irinotecan were included. Furthermore, patients with KRAS wild type tumours should had received EGFR-directed therapy. RESULTS: Conventional chemotherapeutic agents as capecitabine, mitomycin C, and gemcitabine have limited or no activity. Retreatment with oxaliplatin might be an option in selected patients. In addition, rechallenge with EGFR-directed therapy might be a valuable strategy. Data also suggest that angiogenetic drugs may postpone further progression and prolong survival. Lately, regorafinib has been approved. In conclusion, our current knowledge is based on many retrospective studies, some phase II studies and very few randomized clinical trials. Further prospective phase III trials comparing an investigational drug or combination with best supportive care in third- or later lines of treatment in metastatic colorectal cancer are highly warranted. Identification of predictive biomarkers and improvement of our understanding of molecular mechanisms is crucial.