621 - Is adjuvant chemotherapy (CT) beneficial to stage II colon cancer (CC) with elastic laminanl invasion (ELI)?

Date 28 September 2012
Event ESMO Congress 2012
Session Publication Only
Topics Anti-Cancer Agents & Biologic Therapy
Colon Cancer
Presenter Mitsuru Yokota
Authors M. Yokota1, M. Kojima2, S. Nomura3, A. Koyama4, M. Sugito4, M. Ito4, A. Kobayashi4, Y. Nishizawa4, A. Ochiai2, N. Saito4
  • 1Colorectal (pelvic) Surgery Dept., National Cancer Center Hospital East, 277-8577 - Kashiwa/JP
  • 2Research Center For Innovative Oncology, Pathology, National Cancer Center Hospital East, 277-8577 - Kashiwa/JP
  • 3Resarch Center For Innovative Oncology, Clinical Trial Section, National Cancer Center Hospital East, 277-8577 - Kashiwa/JP
  • 4Department Of Gastrointestinal Oncology, Colorectal Surgery, National Cancer Center Hospital East, 277-8577 - Kashiwa/JP

Abstract

Background

The peritoneal elastic lamina (PEL) is situated just under the visceral peritoneum and invests intestine wall. We defined cases with tumor invasion beyond the PEL as positive for ELI (ELI (+)). We have reported that PEL can be a useful pathologic hallmark to classify the level of tumor invasion in CC, and represented as an independent risk factor for recurrence free survival (RFS) for stage II CC (Kojima et al. Am J Surg Pathol. 2010;34:1351-60). We evaluated the necessity of adjuvant CT for stage II CC with ELI (+).

Methods

We screened a database of 436 patients (pts) who underwent curative resection for pT3 and pT4a CC in our hospital between 1996 and 2006, excluding 3 stage II pts who received adjuvant CT. RFS and overall survival (OS) were analyzed to assess the prognostic characteristics of stage II pts with ELI (+). Of 436 pts in the database, we performed Cox regression analysis. Covariates included age (<65/ ≥ 65), gender (male/female), tumor size (<4.5cm/ ≥ 4.5cm), histological type (tub/por and muc), type of surgery (open/laparoscopic), lymphatic invasion (+/-), venous invasion (+/-), lymph node metastasis (N) (0/1-2), number of lymph node retrieval (<12/ ≥ 12), preoperative CEA (<5/ ≥ 5), adjuvant CT (received (+)/not received (-)) and ELI (+/-). Group of pts with N0 and ELI (+) was compared with other groups, consisting of the prognostic factors detected by multiple regression analysis.

Results

3 unfavorable factors were significantly associated with RFS, N1 or N2, ELI (+) and adjuvant CT (-). Total of 6 groups were identified by the above 3 factors. Group 3 of pts with N0, ELI (+) and adjuvant CT (-) had a better prognosis than group 5 and a similar prognosis to group 2 and 4 (Table).

Conclusions

Adjuvant CT may be promising for stage II CC with ELI (+), so this is worth evaluating in the future prospective study. Disclosure: All authors have declared no conflicts of interest.

Table: 621

Group 5-year RFS HR [95% CI] 5-year OS HR [95% CI]
1 N0,ELI(-),AC(-) n = 166 91.1% 0.49 [0.27-0.90] 98.1% 0.59 [0.25-1.41]
2 N1-2,ELI(-),AC(+) n = 42 83.0% 0.77 [0.35-1.69] 97.6% 0.88 [0.29-2.62]
3 N0,ELI(+),AC(-) n = 84 78.3% 1.00 91.2% 1.00
4 N1-2,ELI(+),AC(+) n = 29 69.0% 1.36 [0.62-2.98] 89.7% 1.81 [0.61-5.41]
5 N1-2,ELI(-),AC(-) n = 46 57.7% 1.92 [1.03-3.57] 82.0% 2.10 [0.88-5.01]
6 N1-2,ELI(+),AC(-) n = 69 55.9% 2.36 [1.36-4.11] 79.5% 2.64 [1.20-5.81]

AC = adjuvant chemotherapy, HR = hazard ratio, CI = confidence interval

Disclosure

All authors have declared no conflicts of interest.