Sphincter-sparing resection for rectal cancer

Shared Decision-Making, Sphincter Preservation, and Rectal Cancer Treatment: Identifying and Executing What Matters Most to Patients

Rectal cancer treatment often encompasses multiple steps and options, with benefits and risks that vary based on the individual. Additionally, patients facing rectal cancer often have preferences regarding overall quality of life, which includes bowel function, sphincter preservation, and ostomies. This article reviews these data in the context of shared decision-making approaches in an effort to better inform patients deliberating treatment options for rectal cancer.

Artificial intelligence in rectal cancer

Accurate and rapid diagnosis is essential for correct treatment in rectal cancer. Determining the optimal treatment plan for a patient with rectal cancer is a complex process, and the oncological results and toxicity are not the same in every patient with the same treatment at the same stage. In recent years, the increasing interest in artificial intelligence in all fields of science has also led to the development of innovative tools in oncology. Artificial intelligence studies have increased in many steps from diagnosis to follow-up in rectal cancer. It is thought that artificial intelligence will provide convenience in many ways from personalized treatment to reducing the workload of the physician. Prediction algorithms can be standardized by sharing data between centers, diversifying data, and creating big data.

Machine learning for prediction of chemoradiation therapy response in rectal cancer using pre-treatment and mid-radiation multi-parametric MRI

PURPOSE

To predict the neoadjuvant chemoradiation therapy (CRT) response in patients with locally advanced rectal cancer (LARC) using radiomics and deep learning based on pre-treatment MRI and a mid-radiation follow-up MRI taken 3-4 weeks after the start of CRT.

METHODS

A total of 51 patients were included, 45 with pre-treatment, 41 with mid-radiation therapy (RT), and 35 with both MRI sets. The multi-parametric MRI protocol included T2, diffusion weighted imaging (DWI) with b-values of 0 and 800 s/mm², and dynamic-contrast-enhanced (DCE) MRI. After completing CRT and surgery, the specimen was examined to determine the pathological response based on the tumor regression grade. The tumor ROI was manually drawn on the post-contrast image and mapped to other sequences. The total tumor volume and mean apparent diffusion coefficient (ADC) were measured. Radiomics using GLCM texture and histogram parameters, and deep learning using a convolutional neural network (CNN), were performed to differentiate pathologic complete response (pCR) vs. non-pCR, and good response (GR) vs. non-GR.

RESULTS

Tumor volume decreased and ADC increased significantly in the mid-RT MRI compared to the pre-treatment MRI. For predicting pCR vs. non-pCR, combining ROI and radiomics features achieved an AUC of 0.80 for pre-treatment, 0.82 for mid-RT, and 0.86 for both MRI together. For predicting GR vs. non-GR, the AUC was 0.91 for pre-treatment, 0.92 for mid-RT, and 0.93 for both MRI together. In deep learning using CNN, combining pre-treatment and mid-RT MRI achieved a higher accuracy compared to using either dataset alone, with AUC of 0.83 for predicting pCR vs. non-pCR.

CONCLUSION

Radiomics based on pre-treatment and early follow-up multi-parametric MRI in LARC patients receiving CRT could extract comprehensive quantitative information to predict final pathologic response.

The fate of preserved sphincter in rectal cancer patients

PURPOSE

Sphincter-saving surgery is widely accepted operative modality to treat rectal cancer. It often requires temporary diverting stoma to avoid the complications of anastomotic failure. This study investigates the cumulative failure rate in sphincter preservation for rectal cancer and the risk factors associated with the permanent stoma.

METHODS

A retrospective study on 358 patients diagnosed with primary rectal cancer from 2009 to 2013 was conducted at a single institute. Three hundred and thirty-one out of 358 patients with rectal cancer located within 12 cm from the anal verge, who underwent sphincter-preserving surgery, were included in this study. The cumulative rate for permanent stoma was calculated. Univariate and multivariate analysis were performed, comparing the patients with stoma to the ones without.

RESULTS

Temporary diverting stoma was created in 223 (82%) patients. After median follow-up of 42 months, 18 patients (6.6%) persistently used temporary stoma or required re-creation of stoma. Univariate analysis revealed that BMI, tumor location below 4 cm from the anal verge, coloanal anastomosis, anastomotic leakage, and local recurrence were significantly associated with persistent use or re-formation of stoma. Multivariate analysis showed that anastomotic leakage (OR 50.3; 95% CI, 10.1-250.1; p < 0.0001) and local recurrence (OR 11.3; 95% CI, 1.61-78.5; p = 0.015) were the independent risk factors.

CONCLUSION

Patients with anastomotic leakage and local recurrence are at high risk for permanent stoma. Not only should patients be fully informed of possible failure in sphincter preservation preoperatively, but also patient-oriented decision should be made on patient-tailored surgical plan.

Predictors for local recurrence and distant metastasis of mucinous colorectal adenocarcinoma

BACKGROUND

Mucinous adenocarcinoma (MA) is a unique subtype of colorectal carcinoma. Although some investigators considered MA a predictor for poor prognosis, predictors for poor clinical outcome of MA were not elucidated. The present study aimed to investigate the predictors for local recurrence and distant metastasis of MA.

METHODS

This was a retrospective review of patients with MA who underwent operation with curative intent. Variables included patient and tumor characteristics, TNM stage, investigations, details of surgery, and postoperative outcomes, including local recurrence and distant metastasis. Univariate and multivariate regression analyses were performed to determine the risk factors for local and systemic disease recurrence.

RESULTS

A total of 106 patients (83 male) of a mean age of 51.5 years were included; 62% of patients had colonic tumors, and 38% had rectal tumors; 77% and 58% of colonic and rectal cancers, respectively, were T3-T4 tumors. There were no lymph node metastases in 61% of colonic tumors and 55% of rectal tumors. Local recurrence occurred in 15 patients (14%) and distant metastasis in 9 (9%). Predictors for local recurrence were age (odds ratio [OR]: 1.04; P = .04), female sex (OR: 4.5; P = .01), rectal tumors (OR: 3.73; P = .02), and T4 tumors (OR: 10.9; P = 0.03). Predictors for distant metastasis were age (OR: 1.1; P = .016), local recurrence (OR: 24.28; P < .0001), and T4 tumors (OR: 19.3; P = .049).

CONCLUSION

Patients' age, female sex, and T4 tumors were significant predictors for local recurrence and distant metastasis. Rectal tumors had a greater likelihood for regional recurrence than colonic tumors. Local recurrence was an independent risk factor for distant metastasis.

Low rectal cancer: Sphincter preserving techniques-selection of patients, techniques and outcomes

Low rectal cancer is traditionally treated by abdominoperineal resection. In recent years, several new techniques for the treatment of very low rectal cancer patients aiming to preserve the gastrointestinal continuity and to improve both the oncological as well as the functional outcomes, have been emerged. Literature suggest that when the intersphincteric resection is applied in T1-3 tumors located within 30-35 mm from the anal verge, is technically feasible, safe, with equal oncological outcomes compared to conventional surgery and acceptable quality of life. The Anterior Perineal PlanE for Ultra-low Anterior Resection technique, is not disrupting the sphincters, but carries a high complication rate, while the reports on the oncological and functional outcomes are limited. Transanal Endoscopic MicroSurgery (TEM) and TransAnal Minimally Invasive Surgery (TAMIS) should represent the treatment of choice for T1 rectal tumors, with specific criteria according to the NCCN guidelines and favorable pathologic features. Alternatively to the standard conventional surgery, neoadjuvant chemo-radiotherapy followed by TEM or TAMIS seems promising for tumors of a local stage T1sm2-3 or T2. Transanal Total Mesorectal Excision should be performed only when a board approved protocol is available by colorectal surgeons with extensive experience in minimally invasive and transanal endoscopic surgery.

Sphincter preservation rates after radical resection for rectal cancer in the United States veteran population: opportunity for improvement in early disease

BACKGROUND

Sphincter preservation (SP) is an important goal of rectal cancer surgery. We hypothesized that SP rates among veteran patients have increased and are comparable to national rates, and that a subset of patients with early disease still undergo non-SP procedures.

METHODS

Patients with nonmetastatic primary rectal adenocarcinoma who underwent curative-intent rectal resection were identified from the Veterans Affairs Central Cancer Registry (VACCR) database (1995-2010). SP trends over time were described and compared to the Surveillance, Epidemiology, and End-Results (SEER) population. Subset analysis was performed in patients with nonirradiated, pathologic stage 0-I rectal cancers, a population that may qualify for novel SP strategies.

RESULTS

Of 5,145 study patients, 3,509 (68 %) underwent SP surgery. The VACCR SP rate increased from 59.9 % in 1995-1999 to 79.3 % in 2005-2010, when it exceeded that of SEER (76.9 %, p = 0.023). On multivariate analysis, recent time period was independently associated with higher likelihood of SP (odds ratio [OR] 2.64, p < 0.001). Preoperative radiotherapy (OR 0.51, p < 0.001) and higher pathologic stage (OR 0.37, stage III, p < 0.001) were negative predictors. In patients with nonirradiated pathologic stage 0-I cancers, SP rates also increased, but 25 % of these patients underwent non-SP procedures. Within this subset, patients with clinical stage 0 and I disease still had significant rates of abdominoperineal resection (7.7 and 17.0 %, respectively).

CONCLUSIONS

SP rates among veterans have increased and surpass national rates. However, an unacceptable proportion of patients with stage 0-I rectal cancers still undergo non-SP procedures. Multimodal treatment with local excision may further improve SP rates in this subset of patients.

Multi-institutional assessment of sphincter preservation for rectal cancer

BACKGROUND

Sphincter-preserving surgery (SPS) has been proposed as a quality measure for rectal cancer surgery. However, previous studies on SPS rates lack critical clinical characteristics, rendering it unclear if variation in SPS rates is due to unmeasured case-mix differences or surgeons' selection criteria. In this context, we investigate the variation in SPS rates at various practice settings.

METHODS

Ten hospitals in the Michigan Surgical Quality Collaborative collected rectal cancer-specific data, including tumor location and reasons for non-SPS, of patients who underwent rectal cancer surgery from 2007 to 2012. Hospitals were divided into terciles of SPS rates (frequent, average, and infrequent). Patients were categorized as 'definitely SPS eligible' a priori if they did not have any of the following: sphincter involvement, tumor <6 cm from the anal verge, fecal incontinence, stoma preference, or metastatic disease. Fixed-effects logistic regression was used to evaluate for factors associated with SPS.

RESULTS

In total, 329 patients underwent rectal cancer surgery at 10 hospitals (5/10 higher volume, and 6/10 major teaching). Overall, 72 % had SPS (range by hospital 47-91 %). Patient and tumor characteristics were similar between hospital terciles. On multivariable analysis, only hospital ID, younger age, and tumor location were associated with SPS, but not sex, race, body mass index, American Joint Committee on Cancer (AJCC) stage, preoperative radiation, or American Society of Anesthesiologists (ASA) class. Analysis of the 181 (55 %) 'definitely-eligible' patients revealed an SPS rate of 90 % (65-100 %).

CONCLUSIONS

SPS rates vary by hospital, even after accounting for clinical characteristics using detailed chart review. These data suggest missed opportunities for SPS, and refute the general hypothesis that hospital variation in previous studies is due to unmeasured case-mix differences.

Bursectomy in gastric cancer surgery: surgical technique and operative safety

Although there is little evidence that bursectomy has clinical benefit, its continuing practice imposes evaluation of bursectomy-related adverse effects, especially pancreatic fistula and intestinal obstruction. The aims of this study were to provide a detailed description of the technique of bursectomy as standardized by the authors and determine if extended surgery for gastric cancer with additional bursectomy can be performed safely in Western population. A total of 72 consecutive patients of median age 76.4 years and mean ASA score grade 2.1, who submitted to D2 or D2+ gastrectomy with additional bursectomy for gastric adenocarcinoma, were prospectively studied. Bursectomy was associated with a median additional operative time of 41 min and a median additional blood loss of 65 ml. The post-operative morbidity rate was 19.4 %. Among various adverse events, pancreatic fistula was observed in three patients (4.2 %) and intestinal obstruction was observed in eight patients (11.1 %) including two cases of delayed gastric emptying, one case of afferent loop syndrome, one case of early postoperative adhesions and four cases of prolonged postoperative ileus. The in-hospital mortality rate was 1.4 %. D2 or D2+ gastrectomy with additional bursectomy can be safely performed in Western patients. Although the incidence of pancreatic fistula that we reported was low, the incidence of bursectomy-related intestinal obstruction was high and should always be kept in mind when performing extended surgery for gastric cancer.

Current status of robotic rectal cancer surgery

SUMMARY After the introduction of robotic surgery for rectal cancer, the safety and feasibility of robotic rectal cancer surgery was demonstrated. However, early comparative studies between laparoscopic and robotic surgery did not show a significant postoperative benefit. Recently, it was reported that robotic rectal surgery showed better postoperative outcomes than laparoscopic surgery with regard to postoperative recovery, pain and function preservation. In addition, robotic transanal specimen extraction was safely performed while maintaining a lower level of postoperative pain and recovery time. All of these findings should be validated with well-designed comparative studies. As robotic technology advances and continues to be studied, the use of robotic surgical systems will become more common among colorectal surgeons.

Multimodality salvage of recurrent disease after local excision for rectal cancer

BACKGROUND

Local excision, alone or in combination with chemoradiation, is increasingly considered for rectal cancer. Higher risks of disease recurrence have been demonstrated after local excision.

OBJECTIVE

The aim of this study was to examine the outcomes of current-era multimodality salvage for recurrent rectal cancer after local excision.

DESIGN

This was a single-institutional retrospective study.

SETTINGS

This study was conducted at a tertiary-referral cancer center between 1993 and 2011.

PATIENTS

Forty-six patients with recurrent rectal cancer after initial local excision were included.

INTERVENTION

Multimodality salvage treatment was performed as appropriate.

MAIN OUTCOME MEASURES

The primary outcomes measured were the pattern of disease recurrence, salvage treatments, and resultant overall and re-recurrence-free survival.

RESULTS

After the initial local excision, recurrent disease was diagnosed after a median interval of 1.9 years: local/regionally in 67%, distantly in 18%, and both in 15%. Four patients (9%) had recurrence that was unsalvageable, 2 (4%) declined treatment, and 40 (87%) underwent surgical salvage. Preoperative chemoradiation was given in 30 (75%) patients. The R0 resection rate was 80%, requiring multivisceral resection (33%), total pelvic exenteration (5%), and metastasectomy (25%). The rate of sphincter preservation was 33%, and perioperative morbidity was 50%. The first site of failure after salvage was distant in 38% and was local only in 10%. The 5-year overall and 3-year re-recurrence-free survival were 63% and 43%. Pathologic stage at initial local excision, receipt of neoadjuvant chemoradiation before local excision, recurrence pattern after local excision, pathologic stage at salvage, and R0 resection at salvage influenced re-recurrence-free survival.

LIMITATIONS

This study was limited by the referral and selection biases inherent in a small study cohort.

CONCLUSIONS

Failure after local excision for rectal cancer may not be salvageable. When feasible, multimodality treatment, including multivisceral resection, pelvic irradiation, and chemotherapy, was associated with potentially lasting treatment-related morbidities and only modest success in long-term disease control. These findings should be compared with the expected stage-specific outcomes of standard proctectomy for early-stage rectal cancer, when local excision is being considered.

What is a safe distal resection margin in rectal cancer patients treated by low anterior resection without preoperative radiotherapy?

AIM

The aim of this study was to examine what constitutes an acceptable distal resection margin (DRM) when performing sphincter-saving surgery for rectal cancer without preoperative radiotherapy.

METHOD

This national study consisted of 3571 patients for whom information on DRM was available and who were radically treated by anterior resection between 1993 and 2004. Of these, 3342 (93.5%) patients had not received preoperative radiotherapy. The DRM was measured on fixed specimens.

RESULTS

The 5-year local recurrence rate was 14.5% for patients with a DRM of 0-10 mm compared to 9.6% for patients with a DRM of 11-20 mm, 8.9% for a DRM of 21-30 mm, 7.0% for a DRM of 31-40 mm, 7.7% for a DRM of 41-50 mm and 8.7% for a DRM of > 50 mm. After adjustment for other independent prognostic factors, a DRM of 0-10 mm was found to have significant impact on local recurrence. The DRM had no impact on distant metastases or overall survival.

CONCLUSION

For rectal cancer patients treated without radiotherapy, a DRM of > 10 mm is recommended.