The Current and Evolving Role of Immunotherapy in Metastatic Colorectal Cancer.

Immunotherapy can be considered a therapeutic revolution in oncology, with great impact on many tumor types, such as melanoma and non-small cell lung cancer. However, in metastatic colorectal cancer, the benefits in terms of prolonged tumor control and high response rate are limited to the rare subgroup of tumors with high mutation burden - mostly tumors that harbor microsatellite instability (MSI) or a deficient mismatch repair system (dMMR), or tumor microsatellite stability and damaging mutations in the exonuclease domains of POLE or POLD. The KEYNOTE-028 uncontrolled phase II trial demonstrated an impressive antitumor activity of pembrolizumab in patients with treatmentrefractory Lynch-associated tumors, including colorectal cancer. Nivolumab with or without ipilimumab confirmed the efficacy of immune checkpoint inhibitors in patients with previously treated dMMR / MSI metastatic colorectal cancer. The recent KEYNOTE-177 phase III trial demonstrated that pembrolizumab significantly reduced the relative risk of disease progression or death and improved progression-free survival in patients with treatment-naive dMMR / MSI metastatic colorectal cancer in comparison with first-line chemotherapy with or without biologics. Unfortunately, current pharmacological strategies with immunotherapy have not been successful for most patients with microsatellite stable metastatic colorectal cancer. In this review, we critically appraise the applicability of immune checkpoint inhibitors in dMMR/MSI metastatic colorectal cancer. We also discuss the recent negative trials of immunotherapy combinations in microsatellite stabl.

Outcomes of Patients With Metastatic Anal Cancer According to HIV Infection: A Multicenter Study by the Latin American Gastrointestinal Oncology Group (SLAGO).

BACKGROUND: HIV-positive patients are underrepresented in clinical trials of metastatic squamous cell carcinoma of the anal canal (mSCCA). We aimed to compare the clinical outcomes of mSCCA patients according to HIV infection. METHODS: This was a retrospective multicenter cohort study of consecutive patients with mSCCA. All HIV-positive patients received antiretroviral therapy. The primary endpoint was overall survival (OS), and secondary endpoints were progression-free survival (PFS) and response rate (RR). RESULTS: From January 2005 to December 2019, 113 patients were included: 20 (17.6%) had HIV infection. HIV-positive patients were younger at diagnosis and more frequently male, and 20% (n = 8) received exclusively best supportive care in comparison with 8.6% of HIV-negative patients (P = .13). Both groups were similar in terms of Eastern Cooperative Oncology Group (ECOG) performance status, pattern of metastatic disease, and type of first-line chemotherapy. Five (25%) HIV-positive and 36 (38.7%) HIV-negative patients received second-line therapies (P = .24). RR and median PFS in first-line were similar between the groups: 35% and 30.1% (P = .78) and 4.9 and 5.3 months (P = .85) for patients with and without HIV infection, respectively. At a median follow-up of 26 months, median OS was 11.3 months (95% confidence interval [CI] 10.1 to 26.4) for HIV-infected patients versus 14.6 months (95% CI 11.1 to 18.1) for HIV-negative patients (P = .92). In the univariate analysis for OS, only ECOG performance status was significant. CONCLUSION: HIV-positive mSCCA patients under antiretroviral therapy have oncological outcomes similar to those of HIV-negative patients. These patients should be included in trials of mSCCA.

Disease-Free Survival and Time to Complete Response After Definitive Chemoradiotherapy for Squamous-Cell Carcinoma of the Anus According to HIV Infection.

BACKGROUND: The standard treatment for localized squamous-cell carcinoma of the anal canal is definitive chemoradiotherapy. A meta-analysis of published studies conducted by our group showed significantly lower rates of disease-free survival (DFS) and overall survival at 3 years among HIV-positive patients. We aimed to compare detailed treatment outcomes between the groups of HIV-positive and -negative patients. PATIENTS AND METHODS: We performed a retrospective multicenter study of a comparative cohort of consecutive patients with histologic diagnosis of localized squamous-cell carcinoma of the anal canal who received definitive chemoradiotherapy. Patients' characteristics and outcomes were compared according to HIV status. The primary end points were time to complete response (CR) and DFS time. RESULTS: From June 2001 to September 2018, a total of 185 patients were included; 43 (30.2%) were HIV positive and 142 (69.8%) were HIV negative. The overall CR rates were 67.4% and 91.5% for HIV-positive and -negative patients, respectively (P < .001). The median follow-up was 47.8 months and the median time to experience CR was 7.8 months (95% confidence interval [CI], 5.7-10.5) for HIV-positive versus 4.89 months (95% CI, 4.54-5.25) for HIV-negative (P < .001) patients. The median DFS times were 79.7 months (95% CI, 56.8-102.6) and 127.9 months (95% CI, 112.6-143.2) for HIV-positive and -negative patients, respectively (P = .02). There was a trend toward greater grade 3/4 toxicity in the HIV-positive group. CONCLUSION: HIV-positive patients take longer to experience CR and present worse DFS. These findings have clinical implications because waiting longer to define CR among these patients may prevent unnecessary anorectal amputations.