Controversial Issues Regarding Obligatory Adjuvant Chemotherapy for Stage IIIA Colon Cancer

Is the prognosis of T1-2N1 colon cancer the same as that of T1-2N0 colon cancer after curative surgery?

Objectives: The prognoses of T1-2N0 and T1-2N1 colon cancer after curative surgery remain unclear. This study compared the prognoses of patients with T1-2N0 and T1-2N1 colon cancer after curative surgery.Materials and methods: We retrospectively evaluated 307 consecutive patients with T1-2N0/1 colon cancer who underwent radical surgery at our hospital between January 2010 and December 2016. There were 266 patients with T1-2N0 colon cancer and 41 patients with T1-2N1 colon cancer. After excluding patients with <12 retrieved lymph nodes, 179 patients with T1-2N0 and 32 with T1-2N1 colon cancer were included in the cohort.Results: Overall survival and disease-free survival did not differ between the T1-2N0 and T1-2N1 groups (p = 0.498 and p = 0.681, respectively). Overall survival and disease-free survival were not significantly different between the T1-2N1 + no chemotherapy and T1-2N1 + chemotherapy groups (p = 0.740 and p = 0.765, respectively). Additionally, overall survival and disease-free survival did not differ between the T1-2N0, T1-2N1 + no chemotherapy, and T1-2N1 + chemotherapy groups (p = 0.757 and p = 0.877, respectively), even after excluding patients with <12 retrieved lymph nodes.Conclusions: T1-2N1 has a prognosis as good as that of T1-2N0 colon cancer after curative surgery. Moreover, further research is needed to investigate the efficacy of adjuvant FOLFOX chemotherapy in T1-2N1.

Re-evaluation of controversial issues in the treatment of cT3N0-2 rectal cancer: a 10-year cohort analysis using propensity-score matching

BACKGROUND

Although neoadjuvant treatment is thought to provide optimal local control for stage II and III rectal cancers, many patients have been reported cured by total mesorectal excision (TME), alone or with additional chemotherapy (CTX).

METHODS

This study retrospectively evaluated outcomes in 2643 patients with cT3N0-2 rectal cancers undergoing curative TME during 2005-2015. Recurrence and survival outcomes were measured in three propensity-score matched groups, consisting of patients who underwent preoperative chemoradiotherapy (CRT) with postoperative CTX (NAPOC), postoperative CRT (POCRT), and exclusively postoperative CTX (EPOCT).

RESULTS

Near-complete or complete TME was conducted in more than 95.9% of patients and 80% of scheduled dose of postoperative CTX was completed in 99%. Except for higher SR rate in the POCRT group than the NAPOC group (p = 0.008), 5-year cumulative local and systemic recurrence (LR and SR) rates were 4.9% and 15.2% for cT3N0, and 4.2% and 21% for cT3N1-2 patients (LR, p = 0.703; SR, 0.065), respectively, with no significant differences associated with treatment exposure (p = 0.11-1). The 5-year cumulative disease-free (75.6% vs 65.7%, p = 0.018) and overall survival (87.1% vs 79.4%, p = 0.018 each) rates were higher in the NAPOC group than the POCRT group with cT3N1-2. However, any significant survival differences were not identified between the NAPOC and EPOCT groups according to tumor sub-stages or locations (p = 0.395-0.971).

CONCLUSIONS

We found any treatment modalities including competent TME and postoperative adjuvant CTX efficiently reducing LR generating robust survival outcome in the propensity-matched cohorts, demanding further randomized controlled trials by clinical sub-stages II-III.