Role of Deficient DNA Mismatch Repair Status in Patients With Stage III Colon Cancer Treated With FOLFOX Adjuvant Chemotherapy: A Pooled Analysis From 2 Randomized Clinical Trials.

IMPORTANCE: The prognostic impact of DNA mismatch repair (MMR) status in stage III colon cancer patients receiving FOLFOX (folinic acid, fluorouracil, and oxaliplatin) adjuvant chemotherapy remains controversial. OBJECTIVE: To determine the association of MMR status with disease-free survival (DFS) in patients with stage III colon cancer treated with FOLFOX. DESIGN, SETTING, AND PARTICIPANTS: The evaluated biomarkers for MMR status were determined from prospectively collected tumor blocks from patients treated with FOLFOX in 2 open-label, phase 3 randomized clinical trials: NCCTG N0147 and PETACC8. The studies were conducted in general community practices, private practices, and institutional practices in the United States and Europe. All participants had stage III colon adenocarcinoma. They were enrolled in NCCTG N0147 from February 2004 to November 2009 and in PETACC8 from December 2005 to November 2009. INTERVENTIONS: Patients in the clinical trials were randomly assigned to receive 6 months of chemotherapy with FOLFOX or FOLFOX plus cetuximab. Only those patients treated with FOLFOX alone were included in the present study. MAIN OUTCOMES AND MEASURES: Association of MMR status with DFS was analyzed using a stratified Cox proportional hazards model. Multivariable models were adjusted for age, sex, tumor grade, pT/pN stage, tumor location, ECOG (Eastern Cooperative Oncology Group) performance status, and BRAF V600E mutational status. RESULTS: Among 2636 patients with stage III colon cancer treated with FOLFOX, MMR status was available for 2501. Of these, 252 (10.1%) showed deficient MMR status (dMMR; 134 women, 118 men; median age, 59 years), while 2249 (89.9%) showed proficient MMR status (pMMR; 1020 women, 1229 men; median age, 59 years). The 3-year DFS rates in the dMMR and pMMR groups were 75.6% and 74.4%, respectively. By multivariate analysis, patients with dMMR phenotype had significantly longer DFS than those with pMMR (adjusted hazard ratio, 0.73; 95% CI, 0.54-0.97; P = .03). CONCLUSIONS AND RELEVANCE: The deficient MMR phenotype remains a favorable prognostic factor in patients with stage III colon cancer receiving FOLFOX adjuvant chemotherapy. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00079274 for the NCCTG N0147 trial and EudraCT identifier: 2005-003463-23 for the PETACC8 trial.

Prospective validation of a lymphocyte infiltration prognostic test in stage III colon cancer patients treated with adjuvant FOLFOX.

BACKGROUND: The prognostic value of lymphocyte infiltration (LI) of colorectal carcinoma (CC) has been demonstrated by several groups. However, no validated test is currently available for clinical practice. We previously described an automated and reproducible method for testing LI and aimed to validate it for clinical use. PATIENTS AND METHODS: According to National Institutes of Health criteria, we designed a prospective validation of this biomarker in patients included in the PETACC8 phase III study. Primary objective was to compare percentage of patients alive and without recurrence at 2 years in patients with high versus low LI (#NCT02364024). Associations of LI with patient recurrence and survival were analysed, and multivariable models were adjusted for treatment and relevant factors. Automated testing of LI was performed on virtual slides without access to clinical data. RESULTS: Among the 1220 CC patients enrolled, LI was high, low and not evaluable in 241 (19.8%), 790 (64.8%) and 189 (15.5%), respectively. Primary objective was met with a 2-year recurrence rate of 14.4% versus 21.1% in patients with high and low LI, respectively (p = 0.02). Patients with high LI also had better disease free survival (DFS) and overall survival (OS). Tumour stage, grade, RAS status and BRAF status were with LI the only prognostic markers in multivariable analysis for OS. Subgroup analyses revealed that high LI had better DFS and OS in mismatch repair (MMR) proficient patients, and in patients without RAS mutation, but not in MMR deficient and RAS mutated patients. CONCLUSION: Although this is the first validation with high level of evidence (IIB) of the prognostic value of a LI test in colon cancers, it still needs to be confirmed in independent series of colon cancer patients.

Prognostic Value of Sterilized Lymph Nodes After Preoperative Chemoradiotherapy for Patients with ypN0 Rectal Cancer.

BACKGROUND: Patients with ypN0 rectal cancer who have received preoperative chemoradiotherapy can be divided into those who initially were node negative and those whose positive nodes have been sterilized by preoperative therapy. The long-term prognosis for ypN0 patients with sterilized lymph nodes (LNS) is unknown. This study aimed to assess the prognostic value of LNS after preoperative chemoradiotherapy for patients with ypN0 rectal cancer. METHODS: From January 2007 to March 2014, 206 patients with ypN0 tumors of the mid or lower rectum treated by chemoradiotherapy and radical surgery were enrolled in the study. Of these 206 patients, 49 had ypN0 tumors with LNS (LNS+ group), and 157 had ypN0 tumors without LNS (LNS- group). The patients in both groups were comparable in terms of tumor characteristics, type of chemoradiotherapy, type of surgery, R0 resection rate, and postoperative complication rate. RESULTS: The mean follow-up period was 40.5 ± 27 months. The 1- and 3-year OS rates in the LNS+ group were respectively 100 and 95.5% versus 99.4 and 91.6% in the LNS- group (P = 0.549). The 1- and 3-year DFS rates in the LNS+ group were respectively 100 and 94.2% versus 94.7 and 87.1% in the LNS- group (P = 0.117). The multivariate analysis showed that the presence of LNS did not affect OS (P = 0.918) or DFS (P = 0.209). CONCLUSIONS: The prognosis is excellent for patients with ypN0 rectal cancer who have LNS after preoperative chemoradiotherapy. The presence of LNS in ypN0 rectal cancer patients after chemoradiotherapy should not be considered a factor for a poor prognosis.

Prognostic impact of immune response in resectable colorectal liver metastases treated by surgery alone or surgery with perioperative FOLFOX in the randomised EORTC study 40983.

AIM: To investigate whether the immune response in colorectal liver metastases is related to progression free survival (PFS) and if this may be influenced by systemic therapy. METHODS: A retrospective central collection of tumour tissue was organised for the European Organisation for Research and Treatment of Cancer (EORTC) study 40983, where patients with colorectal liver metastases were treated by either resection alone or resection with perioperative FOLFOX. Immunostaining on whole slides was performed to recognise T-lymphocytes (CD3+, CD4+, CD8+), B-lymphocytes (CD20+), macrophages (CD68+) and mast cells (CD117+) inside the tumour, at the tumour border (TNI) and in normal liver tissue surrounding the tumour (0.5-2mm from the TNI). Immunological response was compared between treatment arms and correlated to PFS. RESULTS: Tumour tissue and immune response profiles were available for 82 resected patients, 38 in the perioperative chemotherapy arm and 44 in the surgery alone arm. Baseline patient and disease characteristics were similar between the treatment arms. In response to chemotherapy, we observed increased CD3+ lymphocyte and mast cell counts inside the tumour (p<0.01), lower CD4+ lymphocytes in the normal liver tissue (p=0.02) and lower macrophage counts in normal tissue (p<0.01) and at the TNI (p=0.02). High number of CD3+ lymphocyte and mast cells, and high T-cell score were correlated with tumour regression grade (TRG). Prolonged PFS correlated with the presence of mast cells in the tumour (9.8 versus 16.5 months, Hazard ratio (HR) 0.54 p=0.03), higher CD3+ lymphocyte count at the TNI (10.8 versus 22.8 months, HR 0.57, p=0.03) and T-cell score >2 (10.8 versus 38.6 months, HR 0.51, p=0.04). CONCLUSION: Our analyses in the context of a randomised study suggest that chemotherapy influences immune cell profiles, independent of patient characteristics. Immune responses of lymphocytes and mast cells were associated with pathological response to chemotherapy and to increased PFS. High CD3+ lymphocytes at the tumour front and intratumoural mast cells appear to be prognostic for patients with colorectal liver metastases.