Recurrence of rectal cancer on the pelvic sidewall after lateral lymph node dissection.

PURPOSE: Although lateral lymph node dissection has been performed to prevent lateral pelvic recurrence in locally advanced lower rectal cancer, the incidence of lateral pelvic recurrence after this procedure has not been investigated. Therefore, this study aimed to investigate the long-term outcomes of patients who underwent lateral pelvic lymph node dissection, with a particular focus on recurrence patterns. METHODS: This was a retrospective study conducted at a single high-volume cancer center in Japan. A total of 493 consecutive patients with stage II-III rectal cancer who underwent lateral lymph node dissection between January 2005 and August 2022 were included. The primary outcome measures included patterns of recurrence, overall survival, and relapse-free survival. Patterns of recurrence were categorized as lateral or central pelvic. RESULTS: Among patients who underwent lateral lymph node dissection, 18.1% had pathologically positive lateral lymph node metastasis. Lateral pelvic recurrence occurred in 5.5% of patients after surgery. Multivariate analysis identified age > 75 years, lateral lymph node metastasis, and adjuvant chemotherapy as independent risk factors for lateral pelvic recurrence. Evaluation of the recurrence rate by dissection area revealed approximately 1% of recurrences in each area after dissection. CONCLUSION: We demonstrated the prognostic outcome and limitations of lateral lymph node dissection for patients with advanced lower rectal cancer, focusing on the incidence of recurrence in the lateral area after the dissection. Our study emphasizes the clinical importance of lateral lymph node dissection, which is an essential technique that surgeons should acquire.

Hazard function analysis of prognosis after recurrent colorectal cancer.

BACKGROUND AND OBJECTIVES: Mean survival time (MST) is used as the indicator of prognosis in patients with a colorectal cancer (CRC) recurrence. The present study aimed to visualize the changes in death risk after a CRC recurrence using hazard function analysis (HFA) to provide an alternative prognostic indicator to MST. METHODS: The medical records of 725 consecutive patients with a recurrence following R0 radical surgery for CRC were retrospectively reviewed. RESULTS: The five-year, post-recurrence survival rate was 37.8%, and the MST was 3.5 years while the risk of death peaked at 2.9 years post-recurrence. Seven variables were found to predict short-term survival, including the number of metastatic organs ≥ 2, non-surgical treatment for the recurrence, and a short interval before recurrence. In patients with a recurrence in one organ, the MST was four years, the peak time of death predicted by HFA was 2.9 years, and the five-year survival rate was 45.8%. In patients with a surgical resection of the recurrence, the MST was 8 years, the peak time of death was 3.3 years, and the five-year survival rate was 62%. CONCLUSIONS: The present study established a novel method of assessing changes in mortality risk over time using HFA in patients with a CRC recurrence.

Modified neoadjuvant rectal score as a novel prognostic model for rectal cancer patients who underwent chemoradiotherapy.

BACKGROUND: The neoadjuvant rectal score (NAR score) has recently been proposed as a better prognostic model than the conventional TNM classification for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy. We recently developed an apoptosis-detection technique for assessing the viability of residual tumors in resected specimens after chemoradiotherapy. This study aimed to establish an improved prognostic classification by combining the NAR score and the assessment of the apoptosis of residual cancer cells. METHODS: We retrospectively enrolled 319 rectal cancer patients who underwent chemoradiotherapy followed by radical surgery. The recurrence-free survival and overall survival of the four models were compared: TNM stage, NAR score, modified TNM stage by re-staging according to cancer cell viability, and modified NAR score also by re-staging. RESULTS: Downstaging of the ypT stage was observed in 15.5% of cases, whereas only 4.5% showed downstaging of ypN stage. C-index was highest for the modified NAR score (0.715), followed by the modified TNM, TNM, and NAR score. Similarly, Akaike's information criterion was smallest in the modified NAR score (926.2), followed by modified TNM, TNM, and NAR score, suggesting that the modified NAR score was the best among these four models. The overall survival results were similar: C-index was the highest (0.767) and Akaike's information criterion was the smallest (383.9) for the modified NAR score among the four models tested. CONCLUSION: We established a novel prognostic model, for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy, using a combination of apoptosis-detecting immunohistochemistry and neoadjuvant rectal scores.

Laparoscopic or Robotically Assisted Colectomy with a Pfannenstiel Incision Reduces the Incisional Hernia Incidence.

Objectives: The present study examined the incidence of incisional hernia by comparing patients from whom a specimen was extracted either through a Pfannenstiel incision (PI) with an intracorporeal anastomosis or via a midline incision (MI) with an extracorporeal anastomosis. Methods: The records of 370 consecutive patients who underwent a laparoscopic or robotically-assisted colectomy were retrospectively analyzed. Regardless of the clinical symptoms, incisional hernia was objectively diagnosed based on abdominal computed tomography findings. The surgical outcomes and incisional hernia incidence were retrospectively compared between the groups. Propensity score matching (PSM) was used to balance background differences between the groups. Results: Eighty-seven and 283 patients were in the PI group and MI group, respectively. After PSM, 71 patients were selected from each group. The median observation time was 572 and 1110 days in the PI and MI group, respectively. The PI group had no incidence of incisional hernia whereas the MI group had a 14% incidence, demonstrating that the former had significantly fewer incisional hernias (p=0.0014). The median interval from surgery to incisional hernia development was 295 days. The PI with an intracorporeal anastomosis was not associated with an increased complication rate. Conclusions: The PI was preferable for intraoperative specimen extraction owing to the low, associated incidence of incisional hernia.

Does Colorectal Stenting as a Bridge to Surgery for Obstructive Colorectal Cancer Increase Perineural Invasion?

Objectives: To clarify whether self-expandable metallic stent (SEMS) placement for obstructive colorectal cancer (CRC) increases perineural invasion (PNI), thereby worsening the prognosis. Methods: In total, 1022 patients with pathological T3 or T4 colon or rectosigmoid cancer who underwent resection were retrospectively reviewed. The study patients were divided into a no obstruction group (n=693), obstruction without stent group (n=251), and obstruction with stent group (n=78), and factors demonstrating an independent association with PNI, the difference in PNI incidence and severity between groups, and the association between PNI and the duration from SEMS placement to surgery were investigated. Survival analysis was performed for each group. Results: On multivariate analysis, SEMS placement (hazard ratio [HR]: 2.08) was independently associated with PNI whereas SEMS placement was not. PNI occurred in 39%, 45%, and 68% of the no obstruction, obstruction without stent, and obstruction with stent group, respectively. In the obstruction with stent group, the proportion of PNI was not associated with the duration from SEMS placement to surgery. Extramural PNI, an advanced form of PNI, demonstrated no increase with increasing interval. The five-year OS was 86.3%, 76.7%, and 73.1% in no obstruction, obstruction without stent, and obstruction with stent group, respectively. On multivariate analysis, obstruction was an independent risk factor of decreased OS (HR: 1.57) whereas SEMS placement was not. Conclusions: The prognosis was comparable between patients with SEMS placement and those with an obstruction who did not undergo SEMS placement, thus demonstrating that SEMS is a viable, therapeutic option for BTS.

A rare case of localized peliosis hepatis during adjuvant chemotherapy including oxaliplatin mimicking a liver metastasis of colon cancer.

BACKGROUND: Oxaliplatin-based regimens are commonly used as adjuvant chemotherapy following surgery for colorectal cancer. Adverse events associated with oxaliplatin include blue liver, which is caused by sinusoidal dilation and diffuse peliosis hepatis. We report herein a case of localized peliosis hepatis closely resembling a metastatic liver tumor. CASE PRESENTATION: The patient, a 50-year-old male, underwent a robotically assisted colectomy for rectosigmoid colon cancer, which was discovered when hematochezia occurred. The patient received a diagnosis of pStage IIIb and was treated with four courses of CAPOX as adjuvant chemotherapy starting at postoperative month 1. At postoperative month 4, contrast-enhanced computed tomography (CT) of the abdomen revealed a 20-mm, low-density area with heterogeneous internal structure in S6/7 of the liver. Abdominal ultrasound and gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) findings led to a diagnosis of metastatic liver tumor, for which a laparoscopic partial hepatectomy was performed. The resected lesion was a dark reddish-brown nodule with indistinct margins that appeared to be continuous with the surrounding area. Histopathological analysis revealed severe, localized dilatation of the sinusoids and congestion consistent with the gross nodule. Based on these findings, localized peliosis hepatis associated with oxaliplatin-induced sinusoidal damage was diagnosed. CONCLUSIONS: Localized peliosis hepatis associated with oxaliplatin use can be difficult to distinguish from a metastatic liver tumor on imaging studies.