園田 洋史

BACKGROUND: Minimally invasive surgery (MIS), such as laparoscopic and robotic surgery for rectal cancer, is performed worldwide. However, limited information is available on the advantages of MIS over open surgery for multivisceral resection for cases clinically invading adjacent organs. PATIENTS AND METHODS: This was a retrospective propensity score-matching study of consecutive clinical T4b rectal cancer patients who underwent curative intent surgery between 2006 and 2021 at the University of Tokyo Hospital. RESULTS: Sixty-nine patients who underwent multivisceral resection were analyzed. Thirty-three patients underwent MIS (the MIS group), while 36 underwent open surgery (the open group). Twenty-three patients were matched to each group. Conversion was required in 2 patients who underwent MIS (8.7%). R0 resection was achieved in 87.0% and 91.3% of patients in the MIS and open groups, respectively. The MIS group had significantly less blood loss (170 vs. 1130 mL; p < 0.0001), fewer Clavien-Dindo grade ≥ 2 postoperative complications (30.4% vs. 65.2%; p = 0.0170), and a shorter postoperative hospital stay (20 vs. 26 days; p = 0.0269) than the open group. The 3-year cancer-specific survival rate, relapse-free survival rate, and cumulative incidence of local recurrence were 75.7, 35.9, and 13.9%, respectively, in the MIS group and 84.5, 45.4, and 27.1%, respectively, in the open group, which were not significantly different (p = 0.8462, 0.4344, and 0.2976, respectively). CONCLUSION: MIS had several short-term advantages over open surgery, such as lower complication rates, faster recovery, and a shorter hospital stay, in rectal cancer patients who underwent multivisceral resection.

INTRODUCTION: Adjuvant chemotherapy (AC) after radical surgery following preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) is now the standard of care. The identification of risk factors for the discontinuation of AC is important for further improvements in survival. We herein examined the prognostic impact of chemotherapy compliance and its relationship with the prognostic nutritional index (PNI) before surgery. MATERIALS AND METHODS: A total of 335 Stage II-III LARC patients who underwent preoperative CRT between 2003 and 2022 at the University of Tokyo Hospital were retrospectively reviewed. We excluded patients with recurrence during AC and those who had not received AC. The relationship between AC and long-term outcomes and that between PNI values and the duration of AC were examined. RESULTS: Thirty-one patients discontinued AC and 62 continued AC. Recurrence-free survival (RFS) was significantly shorter in patients who discontinued AC (p = 0.0056). The discontinuation of AC was identified as an independent risk factor for RFS (HR 2.24, p = 0.0233). Twenty-one patients were classified as having low PNI (less than 40), which correlated with an older age, low BMI, and incomplete AC. Low PNI was an independent risk factor for a shorter duration of AC (HR 2.53, p = 0.0123). CONCLUSION: The discontinuation of AC was related to poor RFS in patients with LARC undergoing preoperative CRT. Furthermore, a low PNI value was identified as a risk factor for a shorter duration of AC.

PURPOSE: This study aimed to clarify the relationship between changes in elasticity and anorectal function before and after chemoradiotherapy. METHODS: This is a single-center prospective cohort study (Department of Surgical Oncology, The University of Tokyo). We established a technique to quantify internal anal sphincter hardness as elasticity using transanal ultrasonography with real-time tissue elastography. Twenty-seven patients with post-chemoradiotherapy rectal cancer during 2019-2022 were included. Real-time tissue elastography with transanal ultrasonography was performed before and after chemoradiotherapy to measure internal anal sphincter hardness as "elasticity" (hardest (0) to softest (255); decreased elasticity indicated sclerotic changes). The relationship between the increase or decrease in elasticity pre- and post-chemoradiotherapy and the maximum resting pressure, maximum squeeze pressure, and Wexner score were the outcome measures. RESULTS: A decrease in elasticity was observed in 16/27 (59.3%) patients after chemoradiotherapy. Patients with and without elasticity decrease after chemoradiotherapy comprised the internal anal sphincter sclerosis and non-sclerosis groups, respectively. The maximum resting pressure post-chemoradiotherapy was significantly high in the internal anal sphincter sclerosis group (63.0 mmHg vs. 47.0 mmHg), and a majority had a worsening Wexner score (60.0% vs. 18.2%) compared with that of the non-sclerosis group. Decreasing elasticity (internal anal sphincter sclerosis) correlated with a higher maximum resting pressure (r = 0.36); no correlation was observed between the degree of elasticity change and maximum squeeze pressure. CONCLUSION: Internal anal sphincter sclerosis due to chemoradiotherapy may correlate to anorectal dysfunction.

BACKGROUND: The standard treatment for anal squamous cell carcinoma is chemoradiation therapy (CRT), but there is a possibility of over-treatment for early-stage disease. cTisN0 and cT1N0 disease is currently indicated for local excision, but it is unclear whether the indication of local excision can be expanded to cT2N0 disease. METHODS: 126 patients with cTis-T2N0 anal cancer treated at 47 centers in Japan between 1991 and 2015 were included. Patients were first classified into the CRT group and surgical therapy group according to the initial therapy, and the latter was further divided into local excision (LE) and radical surgery (RS) groups. We compared prognoses among the groups, and analyzed risk factors for recurrence after local excision. RESULTS: The CRT group (n = 87) and surgical therapy group (n = 39) showed no difference in relapse-free survival (p = 0.29) and overall survival (p = 0.94). Relapse-free survival curves in the LE (n = 23) and RS groups (n = 16) overlapped for the initial 3 years, but the curve for the LE group went lower beyond (p = 0.33). By contrast, there was no difference in overall survival between the two groups (p = 0.98). In the LE group, the majority of recurrences distributed in locoregional areas, which could be managed by salvage treatments. Muscular invasion was associated with recurrence after local excision (hazard ratio: 22.91, p = 0.011). CONCLUSION: LE may be applied to selected patients with anal cancer of cTis-T2N0 stage. Given the high risk of recurrence in cases with muscular invasion, it may be important to consider close surveillance and additional treatment in such patients.

In Western countries, the gold-standard therapeutic strategy for rectal cancer is preoperative chemoradiotherapy (CRT) following total mesorectal excision (TME), without lateral lymph node dissection (LLND). However, preoperative CRT has recently been reported to be insufficient to control lateral lymph node recurrence in cases of enlarged lateral lymph nodes before CRT, and LLND is considered necessary in such cases. We performed a literature review on aspects of pelvic anatomy associated with rectal surgery and LLND, and then combined this information with our experience and knowledge of pelvic anatomy. In this review, drawing upon research using a 3-dimensional anatomical model and actual operative views, we aimed to clarify the essential anatomy for LLND. The LLND procedure was developed in Asian countries and can now be safely performed in terms of functional preservation. Nonetheless, the longer operative time, hemorrhage, and higher complication rates with TME accompanied by LLND than with TME alone indicate that LLND is still a challenging procedure. Laparoscopic or robotic LLND has been shown to be useful and is widely performed; however, without a sufficient understanding of anatomical landmarks, misrecognition of vessels and nerves often occurs. To perform safe and accurate LLND, understanding the landmarks of LLND is essential.