Prognostic Impact of pT Stage and Peritoneal Invasion in Locally Advanced Colon Cancer

Abstract

BACKGROUND: TNM stage has been identified as an independent variable for local recurrence and survival after colon cancer resection. It is still unclear whether peritoneal invasion (pT4a) is a risk factor for adverse oncologic outcome or whether these patients have better results compared with contiguous organs infiltration (pT4b), independent from nodal status (pN). OBJECTIVE: The purpose of this study was to analyze whether peritoneal invasion is an independent risk factor for worse oncologic outcome after curative colon cancer resection. DESIGN: This was a retrospective analysis with multivariate regression of a prospective database, according to Strengthening the Reporting of Observational Studies in Epidemiology Statement. SETTINGS: The study was conducted in a specialized colorectal unit of a tertiary hospital. PATIENTS: A consecutive series of pT3-pT4a-pT4b patients with colon cancer who underwent curative surgery (1993–2010) were included, and patients with metastasis were excluded. MAIN OUTCOME MEASURES: A multivariate Cox regression analysis was performed to assess independent risk factors for 5-year local recurrence, peritoneal carcinomatosis-like recurrence, disease-free survival, and cancer-specific survival. RESULTS: A total of 1010 patients were analyzed (79.3% pT3, 9.9% pT4a, and 10.8% pT4b). At diagnosis, 22.0% had obstructive symptoms, and 10.5% had bowel perforation. A total of 72.2% of the surgeries were elective, and in 15.6% en bloc resection of contiguous organs was performed. Median follow-up was 62 months (38–100 mo). For the whole group, 5-year actuarial rates were 8.8% for local recurrence, 2.5% for peritoneal carcinomatosis, 75.5% for disease-free survival, and 81.8% for cancer-specific survival. At multivariate analysis, pT4a stage was an independent risk factor for local recurrence (p = 0.002; HR = 3.1), peritoneal carcinomatosis (p = 0.02; HR = 4.9), worse disease-free survival (p = 0.002; HR = 1.9), and cancer-specific survival (p = 0.001; HR = 2.2). When considering only the 566 patients with ≥12 nodes identified, T stage was still associated with higher local recurrence (p = 0.04) and carcinomatosis rate (p = 0.04), as well as worse disease-free (p = 0.009) and cancer-specific survival (p = 0.014). LIMITATIONS: This was a retrospective, single-center study. CONCLUSIONS: pT4a stage is an independent risk factor for worse oncologic outcome after curative colon cancer resection compared with pT3 and pT4b stages. The current pT4a-pT4b classification should be reconsidered. Of note, even in pT4a patients, 5-year carcinomatosis rate does not exceed 6%. See Video Abstract at http://links.lww.com/DCR/A926.

Beyond the NCCN Risk Factors in Colon Cancer: An Evaluation in a Swedish Population-Based Cohort

“…pT3a and b were associated with low risk, node-negative disease, whereas pT3c and definitely pT3d disease was associated with high-risk features and node involvement. Peritoneal involvement (pT4a) correlated with worse HR compared with involvement of other structures (pT4b) confirming what was seen in the national material and another recent large patient series 21,28 . Elevated preoperative CEA indicated more advanced disease, as described previously and included in previous NCCN guidelines, but in this material of patients after radical surgery there was no difference in recurrence rates 1,16,29 .…”

Post‐operative and oncological 3‐year follow‐up outcomes in stage 2 colonic cancer in the emergency and elective setting: a cohort study

“…Recently, another monocentric publication with a longer study period observed poor oncological results in stage 2B patients. 26 There has been increasing interest in the relationship between immune response and prognosis/survival. Local adaptive immune reaction might influence the DFS and OS in colorectal cancer and in the initial stages of CRC (1 and 2).…”

“…However, it should be noted that the number of patients younger than 70 years was higher in pT4b stage, with fewer co‐morbidities and who are more likely to be a candidate for adjuvant treatment. Recently, another monocentric publication with a longer study period observed poor oncological results in stage 2B patients 26 …”

Pelvic exenterations for primary rectal cancer: Analysis from a 10-year national prospective database

“…However, in this series, the effect on oncologic outcome was less obvious when comparing pN+ and pN- patients. Given the importance of pT and pN status in colorectal cancer[34], this issue needs to be further investigated in LAPRC. We confirmed that R status was an independent predictor of LR, which was impaired by five-fold in the event of positive resection margins.…”