Smaller tumor size is associated with poor survival in T4b colon cancer

AIM: To hypothesize that in patients with colon cancer showing heavy intestinal wall invasion without distant metastasis(T4b N0-2M0), small tumor size would correlate with more aggressive tumor behaviors and therefore poorer cancer-specific survival(CSS).METHODS: We analyzed T4 b N0-2M0 colon cancer patients in the Surveillance, Epidemiology and End Results(SEER) database. A preliminary analysis of T4 b N0-2M0 colon cancer patients at the Fudan University Shanghai Cancer Center is also presented.RESULTS: A total of 1734 T4 b N0-2M0 colon cancer patients from the SEER database were included. Kaplan-Meier analysis revealed decreasing CSS with decreasing tumor size(P < 0.001). Subgroup analysis showed a significant association between poorer CSS with smaller tumor size in T4 b N0 patients(P = 0.024), and a trend of association in T4 b N1(P = 0.182) and T4 b N2 patients(P = 0.191). Multivariate analysis identified tumor size as an independent prognostic factor for CSS in T4 b N0-2M0 patients(P = 0.024). Preliminary analysis of Fudan University Shanghai Cancer Center samples suggested the 5-year CSS was 50.0%, 72.9% and 77.1% in patients with tumors ≤ 4.0 cm, 4.0-7.0 cm and ≥ 7.0 cm.CONCLUSION: Smaller tumor size is associated with poorer CSS in the T4 b N0-2M0 subset of colon cancer, particularly in the T4 b N0M0 subgroup.

Standard chemotherapy with cetuximab for treatment of colorectal cancer

AIM: To review and assess the evidence related to cetuximab treatment in metastatic colorectal cancer(mCRC) with regard to KRAS status.METHODS: PubMed, EMBASE, Cochrane database and American Society of Clinical Oncology meeting abstracts were searched for randomized controlled trials(RCTs) reporting the effect of KRAS status on efficacy of chemotherapy regimen with or without cetuximab in mCRC. Baseline information such as sex and age was summarized from the included studies.Hazard ratios of progression-free survival(PFS) and overall survival(OS) as well as objective response based on KRAS status were extracted for analysis.RESULTS: A total of 8 RCTs with 6780 patients were included. The combined analysis showed that cetuximab failed to improve the OS and PFS in patients with mCRC.However, in subgroup analysis, the pooled data showed that addition of cetuximab to irinotecan containing chemotherapy regimen was sufficient to improve OS and PFS in wild-type KRAS mCRC patients, but not in patients with mutant-type KRAS. The addition of cetuximab increased the incidence of adverse events such as diarrhea, rash, skin toxicity/rash, and nausea and vomiting. There was no significant publication bias existing in the included studies.CONCLUSION: The clinical benefit of cetuximab was only confirmed in patients with wild-type KRAS. KRAS status could be considered a biomarker of efficacy of cetuximab.

Laparoscopic vs open abdominoperineal resection in the multimodality management of low rectal cancers

AIM: To evaluate the safety and feasibility of laparoscopic abdominoperineal resection compared with the open procedure in multimodality management of rectal cancer.METHODS: A total of 106 rectal cancer patients who underwent open abdominoperineal resection(OAPR) were matched with 106 patients who underwent laparoscopic abdominoperineal resection(LAPR) in a 1 to 1 fashion, between 2009 and 2013 at Fudan University Shanghai Cancer Center. Propensity score matching was carried out based on age, gender, pathological staging of the disease and administration of neoadjuvant chemoradiation. Data regarding preoperative staging, surgical technique, pathologicalresults, postoperative recovery and complications were reviewed and compared between the LAPR and OAPR groups. Perineal closure around the stoma and pelvic floor reconstruction were performed only in OAPR, not in LAPR. Therefore, abdominoperineal resection procedure-specific surgical complications including parastomal hernia and perineal wound complications were compared between the open and laparoscopic procedure. Regular surveillance of the two cohorts was carried out to gather prognostic data. Diseasefree survival was analyzed using Kaplan-Meier estimate and log-rank test. Subgroup analysis was performed in patients with locally advanced disease treated with preoperative chemoradiation followed by surgical resection. RESULTS: No significant difference was found between the LAPR group and the OAPR group in terms of clinicopathological features. The operation time(180.8 ± 47.8 min vs 172.1 ± 49.2 min, P = 0.190), operative blood loss(93.9 ± 60.0 m L vs 88.4 ± 55.2 m L, P = 0.494), total number of retrieved lymph nodes(12.9 ± 6.9 vs 12.9 ± 5.4, P = 0.974), surgical complications(12.3% vs 15.1%, P = 0.549) and pathological characteristics were comparable between the LAPR and OAPR group, respectively. Compared with OAPR patients, LAPR patients showed significantly shorter postoperative analgesia(2.4 ± 0.7 d vs 2.7 ± 0.6 d, P < 0.001), earlier first flatus(57.3 ± 7.9 h vs 63.5 ± 9.2 h, P < 0.001), shorter urinary drainage time(6.5 ± 3.4 d vs 7.8 ± 1.3 d, P < 0.001), and shorter postoperative admission(11.2 ± 4.7 d vs 12.6 ± 4.0 d, P = 0.014). With regard to APR-specific complications(perineal wound complications and parastomal hernia), there were no significant differences between the two groups. Similar results were found in the 26 pairs of patients administered neoadjuvant chemoradiation in subgroup analysis. During the follow-up period, no port site recurrences were observed. CONCLUSION: Laparoscopic abdominoperineal resection for multidisciplinary management of rectal cancer is safe, and is associated with earlier recovery and shorter admission time in combination with neoadjuvant chemoradiation.