Improved oncologic outcomes with increase of laparoscopic surgery in modified complete mesocolic excision with D3 lymph node dissection for T3/4a colon cancer: results of 1191 consecutive patients during a 10-year period: a retrospective cohort study

Prognostic value of lymph node distribution after laparoscopic colectomy with Japanese D3 dissection

PURPOSE

Positive pathologic lymph nodes in colorectal cancer represent an important prognostic indicator. Whether lymph node distribution or the number of metastatic nodes is more strongly associated with survival prediction remains controversial.

METHODS

Among 3449 colorectal cancer surgeries performed at Nagasaki University Hospital and five affiliated institutions from April 2016 to March 2022, we investigated 604 patients who underwent laparoscopic radical resection and were diagnosed with pathological stage III cancer. Patients were divided into two groups according to whether they had central vessel metastasis (LND3 group, n=42) or not (LND1/2 group, n=562). After adjusting for background factors using propensity score matching, the LND3 group included 42 patients and the LND1/2 group included 40 patients. Patient background characteristics and prognosis were compared between these two groups.

RESULTS

Before matching, frequencies of right-side colon cancer (64.3% vs 38.1%, p=0.001), multivisceral resection (11.9% vs 4.4%, p=0.039), clinical N2 status (40.5% vs 22.6%, p=0.032), and pathological N2 (73.8% vs 22.6%, p<0.001) were all greater, and the number of lymph nodes retrieved was higher (24 vs 19, p=0.042) in the LND3 group. After matching, no differences in any clinical factors were evident between groups. Five-year RFS (44.8% vs 77.1%, p=0.004) and OS (43.1% vs 83.2%, p<0.001) were worse in the LND3 group. Adjuvant chemotherapy improved RFS (adjuvant chemotherapy (+) vs adjuvant chemotherapy (-): 62.1% vs 27.7%, p=0.047) in the LND3 group.

CONCLUSION

LND3-positive patients show poorer prognosis than LND1/2 patients and should be treated with an appropriate perioperative treatment strategy.

Mid-term outcomes of laparoscopic vs open colectomy for pathological T4 and/or N2 colon cancer patients: Multicenter study using propensity score matched analysis

OBJECTIVES

We aimed to assess mid-term outcomes after laparoscopic surgery (LAP) vs open surgery (OP) for pathological T4 (pT4) and/or N2 (pN2) colon cancer.

METHODS

We retrospectively reviewed 255 primary tumor resections for pT4 and/or pN2 colon cancer performed from 2015 to 2020 at six hospitals, divided into LAP (n = 204) and OP groups (n = 51). After propensity score matching to minimize selection bias, 47 matched patients per group were assessed.

RESULTS

Before matching, the rate of males (53.9% vs. 37.3%, P = .042), left sided colon cancer (53.9% vs 37.3%, P = .042), D3 lymph node dissection (90.7% vs 68.6%, P < .001) and body mass index (kg/m2 ) (22.3 vs 21.8, P = .039) were significantly greater in the LAP group. The rate of pT4b (7.8% vs 40.4%, P < .001) was lower and pN2 was higher (57.4% vs 37.3%, P = .012) in the LAP group. After matching, preoperative characteristics and pathologic status were equivalent between the groups. The LAP and OP groups showed comparable overall survival (OS) (2-year OS, 84.5% vs 76.8%, P = .055) and recurrence-free survival (RFS) (2-year RFS, 73.9% vs 52.8%, P = .359). In the patients with pT4, OS (2-year OS, 79.4% vs 75.7%, P = .359) and RFS (2-year RFS, 71.3% vs 58.7%) were comparable. In the patients with pN2, OS (2-year OS, 83.4% vs 76.3%) and RFS (2-year RFS, 69.6% vs 36.2%) were also comparable.

CONCLUSIONS

LAP for pT4 and/or pN2 colon cancer showed comparable mid-term outcomes compared with OP. LAP was an acceptable surgical approach in this cohort.

Definition and reporting of lymphadenectomy and complete mesocolic excision for radical right colectomy: a systematic review

BACKGROUND

Several procedures have been proposed to reduce the rates of recurrence in patients with right-sided colon cancer. Different procedures for a radical right colectomy (RRC), including extended D3 lymphadenectomy, complete mesocolic excision and central vascular ligation have been associated with survival benefits by some authors, but results are inconsistent. The aim of this study was to assess the variability in definition and reporting of RRC, which might be responsible for significant differences in outcome evaluation.

METHODS

PRISMA-compliant systematic literature review to identify the definitions of RRC. Primary aims were to identify surgical steps and different nomenclature for RRC. Secondary aims were description of heterogeneity and overlap among different RRC techniques.

RESULTS

Ninety-nine articles satisfied inclusion criteria. Eight surgical steps were identified and recorded as specific to RRC: Central arterial ligation was described in 100% of the included studies; preservation of mesocolic integrity in 73% and dissection along the SMV plane in 67%. Other surgical steps were inconstantly reported. Six differently named techniques for RRC have been identified. There were 35 definitions for the 6 techniques and 40% of these were used to identify more than one technique.

CONCLUSIONS

The only universally adopted surgical step for RRC is central arterial ligation. There is great heterogeneity and consistent overlap among definitions of all RRC techniques. This is likely to jeopardise the interpretation of the outcomes of studies on the topic. Consistent use of definitions and reporting of procedures are needed to obtain reliable conclusions in future trials. PROSPERO CRD42021241650.