Cetuximab monotherapy and cetuximab plus capecitabine as first-line treatment in older patients with RAS- and BRAF wild-type metastatic colorectal cancer. Results of the multicenter phase II trial SAKK 41/10.

INTRODUCTION: While the anti-VEGF antibody bevacizumab was studied repeatedly as part of low-intensity regimens in less fit elderly patients with metastatic colorectal cancer (mCRC), anti-EGFR antibodies as upfront treatment modality have been scarcely investigated. MATERIAL AND METHODS: In SAKK 41/10, the benefit of cetuximab, either alone or in combination with capecitabine, was evaluated in vulnerable elderly patients with RAS/BRAF-wild-type mCRC. RESULTS AND DISCUSSION: The trial was stopped prematurely due to slow accrual after the inclusion of 24 patients (11 in the monotherapy arm, 13 in the combination arm). Median patient age was 80 years (range 71-89), median CIRS-G score 7 (range 2-13), and median IADL score 7 (range 3-8). At week 12, 6 of 11 patients (55%) were progression-free in the cetuximab monotherapy arm and 9 of 13 patients (69%) in the combination arm. Response rate was 9% in the monotherapy arm and 38% combination arm. The 6 patients with right-sided primary tumors were not responsive to cetuximab. NGS revealed additional mutations affecting the RAS/RAF/MAP kinase pathway in 5 patients; 4 of these patients showed early disease progression. Cetuximab was generally well tolerated and a trend toward an improvement of symptom-related QoL was observed. In the combination arm, a higher incidence of toxicities and treatment stoppings was observed. In conclusion, trial recruitment - requiring both geriatric as well as molecular eligibility criteria - proved more difficult than expected. Bearing in mind the very small sample size, upfront cetuximab treatment appeared tolerable and showed promising activity in left-sided tumors in both treatment arms.

Early Postoperative FDG-PET-CT Imaging Results in a Relevant Upstaging in the pN2 Subgroup of Stage III Colorectal Cancer Patients.

INTRODUCTION: Clinical practice guidelines regarding follow-up in patients after curative resection of colorectal cancer (CRC) vary widely. Current follow-up recommendations do not include additional postoperative imaging before starting adjuvant treatment in any patients. We evaluated the potential benefit of our institutional approach, recommending 18fluor-deoxy-glucose (FDG)-positron emission tomography (PET)-computed tomography (CT) imaging in CRC stage III patients with ≥4 locoregional lymph node metastases (pN2). PATIENTS AND METHODS: Our study included all patients from a single center with complete resection of a pT1-4, pN2, cM0 CRC. All patients were considered free of distant metastases on the basis of preoperative CT imaging of the chest, abdomen, and pelvis. The main objective of the present study was to assess the proportion of patients with changes of therapeutic management (defined as any other treatment than the preplanned adjuvant chemotherapy) because of the results of additional postoperative FDG-PET-CT imaging. RESULTS: Fifty patients (22 female/28 male) were included; the median age was 64 years (range, 37-78 years). Previously undiagnosed metastatic disease resulting in a change of the therapeutic management was detected using postoperative FDG-PET-CT imaging in 7 patients (14.0%; 95% confidence interval, 5.8%-26.7%). The number needed to screen to detect new or previously occult metastases was 7 (7 of 50). CONCLUSION: To our knowledge, this is the first study to evaluate the role of an additional postoperative FDG-PET-CT scan before adjuvant treatment in patients with completely resected CRC with ≥4 lymph node metastases (pT1-4, pN2) and without distant metastases on preoperative CT imaging (cM0). Postoperative FDG-PET-CT imaging represents a valuable tool for the detection of new macrometastases in the subgroup of pN2 cM0 CRC patients. The low number needed to screen for consequent therapeutic changes is clinically relevant and should be further evaluated.

Vascular endothelial growth factor A amplification in colorectal cancer is associated with reduced M1 and M2 macrophages and diminished PD-1-expressing lymphocytes.

VEGFA is an angiogenic factor secreted by tumors, in particular those with VEGFA amplification, as well as by macrophages and lymphocytes in the tumor microenvironment. Here we sought to define the presence of M1/M2 macrophages, PD-1-positive lymphocytes and PD-L1 tumoral and stromal expression in colorectal cancers harboring VEGFA amplification or chromosome 6 polysomy. 38 CRCs of which 13 harbored VEGFA amplification, 6 with Chr6 polysomy and 19 with neutral VEGFA copy number were assessed by immunohistochemistry for CD68 (marker for M1/M2 macrophages), CD163 (M2 macrophages), programmed death 1(PD-1)- tumor infiltrating and stromal lymphocytes as well as tumoral and stromal PD-1 ligand (PD-L1) expression. CRCs with VEGFA amplification or Chr6 polysomy were associated with decreased M1/M2 macrophages, reduced PD-1-expressing lymphocyte infiltration, as well as reduced stromal expression of PD-L1 at the tumor front. Compared to intermediate-grade CRCs, high-grade CRCs were associated with increased M1/M2 macrophages and increased tumoral expression of PD-L1. Our results suggest that VEGFA amplification or Chr6 polysomy is associated with an altered tumor immune microenvironment.

Relative survival is an adequate estimate of cancer-specific survival: baseline mortality-adjusted 10-year survival of 771 rectal cancer patients.

BACKGROUND: The objective of the present investigation is to assess the baseline mortality-adjusted 10-year survival of rectal cancer patients. METHODS: Ten-year survival was analyzed in 771 consecutive American Joint Committee on Cancer (AJCC) stage I-IV rectal cancer patients undergoing open resection between 1991 and 2008 using risk-adjusted Cox proportional hazard regression models adjusting for population-based baseline mortality. RESULTS: The median follow-up of patients alive was 8.8 years. The 10-year relative, overall, and cancer-specific survival were 66.5% [95% confidence interval (CI) 61.3-72.1], 48.7% (95% CI 44.9-52.8), and 66.4% (95% CI 62.5-70.5), respectively. In the entire patient sample (stage I-IV) 47.3% and in patients with stage I-III 33.6 % of all deaths were related to rectal cancer during the 10-year period. For patients with AJCC stage I rectal cancer, the 10-year overall survival was 96% and did not significantly differ from an average population after matching for gender, age, and calendar year (p = 0.151). For the more advanced tumor stages, however, survival was significantly impaired (p < 0.001). CONCLUSIONS: Retrospective investigations of survival after rectal cancer resection should adjust for baseline mortality because a large fraction of deaths is not cancer related. Stage I rectal cancer patients, compared to patients with more advanced disease stages, have a relative survival close to 100% and can thus be considered cured. Using this relative-survival approach, the real public health burden caused by rectal cancer can reliably be analyzed and reported.