Planes of sharp pelvic dissection for primary, locally advanced, or recurrent rectal cancer

Mid-term oncological outcomes after complete versus conventional mesocolic excision for right-sided colon cancer: a propensity score matching analysis

BACKGROUND

The correct extent of mesocolic dissection for right-sided colon cancer (RCC) is still under debate. Complete mesocolic excision (CME) has not gained wide diffusion, mainly due to its technical complexity and unclear oncological superiority. This study aims to evaluate oncological outcomes of CME compared with non-complete mesocolic excision (NCME) during resection for I-III stage RCC.

METHOD

Prospectively collected data of patients who underwent surgery between 2010 and 2018 were retrospectively analysed. 1:1 Propensity score matching (PSM) was used to balance baseline characteristics of CME and NCME patients. The primary endpoint of the study was local recurrence-free survival (LRFS). The two groups were also compared in terms of short-term outcomes, distant recurrence-free survival, disease-free survival, and overall survival.

RESULTS

Of the 444 patients included in the study, 292 were correctly matched after PSM, 146 in each group. The median follow-up was 45 months (IQR 33-63). Conversion rate, complications, and 90-day mortality were comparable in both groups. The median number of lymph nodes harvested was higher in CME patients (23 vs 19, p = 0.034). 3-year LRFS rates for CME patients was 100% and 95.6% for NCME (log-rank p = 0.028). At 3 years, there were no differences between the groups in terms of overall survival, distant recurrence-free survival, and disease-free survival.

CONCLUSION

Our PSM cohort study shows that CME is safe, provides a higher number of lymph nodes harvested, and is associated with better local recurrence-free survival.

Adjuvant Chemotherapy Benefit in Elderly Stage II/III Colon Cancer Patients

Background

Studies providing more evidence to guide adjuvant chemotherapy decisions in elderly colon cancer patients are expected.

Methods

We obtained data from the Surveillance, Epidemiology and End Results (SEER) database between 2004 and 2012. Kaplan-Meier survival curves were constructed to calculate the cancer-specific survival (CSS) rate, and comparisons of survival difference between different subgroups were performed using the log-rank test. Multivariate Cox proportional hazards regression models were carried out to estimate hazard ratio (HR) and 95% confidence intervals (CIs) of different clinicopathological characteristics.

Results

In stage II colon cancer patients aged 70 years or older, the Kaplan-Meier survival analysis showed that the 5-year CSS rates of no chemotherapy and chemotherapy groups were 82.0% and 72.4%, respectively (P < 0.001). In stage III colon cancer patients aged 70 years or older, the Kaplan-Meier survival analysis showed that the 5-year CSS rates of no chemotherapy and chemotherapy groups were 50.7% and 61.3%, respectively (P < 0.001). Patients with chemotherapy receipt were independently associated with a 35.8% lower cancer-specific mortality rate (HR = 0.642, 95% CI: 0.620-0.665, P < 0.001) compared with those who did not receive chemotherapy.

Conclusions

Adjuvant chemotherapy should be considered during the treatment of stage III colon cancer patients aged 70 years or older, but the chemotherapy benefit in elderly stage II colon cancer is suboptimal.

Complete mesocolic excision versus conventional surgery for colon cancer: A systematic review and meta-analysis

AIM

Complete mesocolic excision (CME) lacks consistent data advocating operative superiority compared to conventional surgery for colon cancer. We performed a systematic review and meta-analysis, analysing population characteristics and perioperative, pathological and oncological outcomes.

METHODS

D3 extended lymphadenectomy dissection was considered comparable to CME, and D2 and D1 dissection to be comparable to conventional surgery. Outcomes reviewed included lymph node yield, R1 resection, overall complications, overall survival and disease-free survival.

RESULTS

In all, 3039 citations were identified; 148 studies underwent full-text reviews and 31 matched inclusion criteria: total cohort 26 640 patients (13 830 CME/D3 vs. 12 810 conventional). Overall 3- and 5-year survival was higher in the CME/D3 group compared with conventional surgery: relative risk (RR) 0.69 (95% CI 0.51-0.93, P = 0.016) and RR 0.78 (95% CI 0.64-0.95, P = 0.011) respectively. Five-year disease-free survival also demonstrated CME/D3 superiority (RR 0.67, 95% CI 0.52-0.86, P < 0.001), with similar findings at 1 and 3 years. There were no statistically significant differences between the CME/D3 and conventional group in overall complications (RR 1.06, 95% CI 0.97-1.14, P = 0.483) or anastomotic leak (RR 1.02, 95% CI 0.81-1.29, P = 0.647).

CONCLUSIONS

Meta-analysis suggests CME/D3 may have a better overall and disease-free survival compared to conventional surgery, with no difference in perioperative complications. Quality of evidence regarding survival is low, and randomized control trials are required to strengthen the evidence base.

Waldeyer's fascia: anatomical location and relationship to neighboring fasciae in retrorectal space

PURPOSE

The term Waldeyer's fascia has caused confusion in surgery for rectal cancer. We have therefore dissected endopelvic fasciae to clarify the structure and location of Waldeyer's fascia, and to determine its anatomical relationships with adjacent fasciae.

METHODS

Twenty cadavers (13 males and 7 females) were dissected. Each specimen was sectioned in the sagittal plane and both hemipelvises were examined.

RESULTS

Waldeyer's fascia was observed in all specimens originating from the presacral fascia at the S2-S4 level and fusing with the posterior leaf of the mesorectal parietal fascia. Waldeyer's fascia divided the retrorectal space (RRS) into inferior and superior compartments, with the upper leaf constituting the floor of the superior compartment and the lower leaf constituting the dome of the inferior compartment. There were no nerves, blood vessels or lymphatic vessels within the two leaves.

CONCLUSION

Waldeyer's fascia was located between the mesorectal parietal and presacral fasciae. Waldeyer's fascia included two leaves, which jointly divided the RRS into inferior and superior compartments. Waldeyer's fascia is a pivotal anatomical structure in the surgical treatment of rectal cancer.

Recent advances in the management of carcinoma of the rectum

In the last two decades rectal cancer has changed from a surgically managed disease into a multidisciplinary treatment model resulting in considerable improvements in the survival and outcome. This has been made possible by better understanding of the tumor biology and oncogenesis, advances in diagnostic and staging investigations, and the changing concepts in surgical excision; from the days of abdominoperineal resection to the concept of "zone of upward spread" and low anterior resection to the era of total mesorectal excision and transanal excision. Efforts are on the way to risk stratification and identification of predictors of nonoperative management. Impressive advances in the adjuvant therapies have seen a sea change in the form of postoperative radiotherapy to preoperative radiotherapy to preoperative chemoradiotherapy and postoperative adjuvant chemotherapy. This multidisciplinary approach is the key to impressive local control rates, decreased metastatic rates, overall survival, and enhancement in quality of life. Newer ideas in the understanding of genetic differences in rectal cancers have stemmed from the observation that these cancers differ in their response to the adjuvant treatment. The present day research has focused these areas of biologic differences in cancers and aims to target the specific loci in malignant cells with monoclonal antibodies directed against various growth factors, key enzyme inhibition, and genetic manipulation. The future research lies in the study of gene expression, micro-array techniques, molecular markers, and better understanding of the predictors of tumor response to therapy.

Standardized surgery for colonic cancer: complete mesocolic excision and central ligation--technical notes and outcome

OBJECTIVE

Total mesorectal excision (TME) as proposed by R.J. Heald more than 20 years ago, is nowadays accepted worldwide for optimal rectal cancer surgery. This technique is focused on an intact package of the tumour and its main lymphatic drainage. This concept can be translated into colon cancer surgery, as the mesorectum is only part of the mesenteric planes which cover the colon and its lymphatic drainage like envelopes. According to the concept of TME for rectal cancer, we perform a concept of complete mesocolic excision (CME) for colonic cancer. This technique aims at the separation of the mesocolic from the parietal plane and true central ligation of the supplying arteries and draining veins right at their roots.

METHOD

Prospectively obtained data from 1329 consecutive patients of our department with RO-resection of colon cancer between 1978 and 2002 were analysed. Patient data of three subdivided time periods were compared.

RESULTS

By consequent application of the procedure of CME, we were able to reduce local 5-year recurrence rates in colon cancer from 6.5% in the period from 1978 to 1984 to 3.6% in 1995 to 2002. In the same period, the cancer related 5-year survival rates in patients resected for cure increased from 82.1% to 89.1%.

CONCLUSION

The technique of CME in colon cancer surgery aims at a specimen with intact layers and a maximum of lymphnode harvest. This is translated into lower local recurrence rates and better overall survival.

Distribution and patterns of lymph nodes metastases and micrometastases in the mesorectum of rectal cancer

BACKGROUND AND OBJECTIVES

Facts buried in the mesorectum remain to be unveiled. This study investigated the number, size, and detailed distribution of lymph nodes metastases and micrometastases within the mesorectum of rectal cancer.

METHODS

Thirty-one patients who underwent total mesorectal excision (TME) were treated with lymph node revealing solution to retrieve lymph nodes, which were submitted to hematoxylin and eosin (HE) examination and immunohistochemical (IHC) staining.

RESULTS

The mean number of mesorectal nodes per case was 17.7. The mean size of metastatic, micrometastatic, and isolated tumor cells (ITC) harbored nodes was 5.2 mm, 4.5 mm, and 3.3 mm, respectively. Most of the metastatic (92.1%), micrometastatic and ITC-involved nodes (69.2%) were located along the superior rectal artery (SRA). Posterior-wall located tumor might spread along both sides of the mesorectum simultaneously (P = 0.34), while lateral-wall located tumor spread preferably to ipsolateral side versus contralateral side (P = 0.012).

CONCLUSION

Most of the metastases and micrometastases positive lymph nodes were smaller than 5 mm and distributed along the SRA. The patterns of lymph nodes spread were related to the circumferential situation of tumor in the rectal wall. Surgical excision of the rectal cancer should completely remove the whole mesorectum, especially to avoid any damage of the mesorectum on tumor side.

Education is the key to quality of surgery for rectal cancer

Surgical quality assurance is a central issue in the treatment of rectal cancer and has led to substantial improvements in sphincter preservation, local control, and overall survival. Education or training as well as volume of practice are often cited as the major predictors of quality outcomes. While volume is a simple measure to analyze, it is likely a superficial or surrogate measure of quality surgery. It has been conclusively demonstrated that education, from total mesorectum excision workshops to nation-wide educational initiatives are effective methods of improving quality of care for the rectal cancer patient. New methods of quality assurance and improvement are being developed including prospective quality registers, the synoptic operative report, and pathology audits. It is imperative that improved measures of quality, other than volume, be implemented to audit our own practices, hospitals and regions with the goal of identifying issues that will improve outcomes for rectal cancer patients.

Accuracy of thin section magnetic resonance using phased-array pelvic coil in predicting the T-staging of rectal cancer

Magnetic resonance (MR) imaging may contribute to staging rectal cancer and inform the decision regarding administration of pre-operative radiotherapy. The accuracy of MR has been debated. The aim of the present study was to determine the accuracy of thin section T2-weighted MR images in rectal cancer patients. MR results were compared with histological assessment of resection specimens. Over a 2-year period, 42 patients were studied. Histological staging was pT2 n = 13, pT3 n = 25 and pT4 n = 4. MR diagnostic accuracy was 74%. MR sensitivity and specificity was 62% and 79% for pT2 lesions, 84% and 59% for pT3 lesions and 50% and 76% for pT4 lesions. Estimation of tumour penetration by thin section MR imaging of rectal cancers using pelvic phased-array coil has moderate diagnostic accuracy. The limitations of MR should be acknowledged when selecting rectal cancer patients for pre-operative radiotherapy.

Treatment of locally advanced rectal cancer

Historically, locally advanced rectal cancer is known for its dismal prognosis. The treatment of locally advanced rectal cancer is subject to continuous change due to development of new and better diagnostic tools, radiotherapeutic techniques, chemotherapeutic agents and understanding of the subject. It is clear, that a multimodality approach is the only way to achieve satisfactory local recurrence and survival rates in this type of cancer. However, which multimodality strategy is to be used still remains a point of controversy. This review summarises recent developments in imaging, (neo-) adjuvant therapy and surgical techniques in the treatment of primary locally advanced rectal cancer.

Surgery for locally recurrent rectal cancer

After the diagnosis of a locally recurrent rectal cancer, imaging is the first step to estimate the extent and location of the local tumour growth and the presence or absence of distant metastases. The aim of the treatment is a R0 resection (microscopically tumour free circumferential margin) by multimodality treatment consisting of pre-operative radiation, extended resection and intra-operative radiotherapy by either electron beam irradiation or with high dose rate brachytherapy. Filling the pelvic cavity with vital tissue such as an omentoplasty should considered carefully. With this treatment the overall three-year survival rate of a group of 33 patients was 60% with a local control rate of 73%. The combination of chemotherapy as a radiosensitizer resulted in an increase of R0 resections by 20%. Introduction of TME surgery and pre-operative radiotherapy has created a new situation with limited possibilities due to dose-accumulation toxicity of the radiotherapy and extensive scarring of the tissues making estimation of the extent of the tumour growth more difficult. The prevention of local recurrence by proper selection of primary cases, the training of experienced surgeons and the optimal use of pre-operative radiotherapy is the way forward to improve results.

Autonomic nerve preserving total mesorectal excision

The main objectives of surgery for rectal cancer are cure and the prevention of local or pelvic recurrence. Preservation of pelvic autonomic functions are important associated goals that have influenced the design of the operation. These changes began with modifications to the art of lateral pelvic lymphadenectomy, and with the introduction of sharp pelvic dissection along anatomical pelvic fascial planes for rectal cancer in the mid-1970s. These changes evolved to include deliberate autonomic nerve preservation as a part of the operation that was ultimately reported as TME with ANP [1]. While it is a small nuance. dissection was generally directed to the widest possible pelvic margin--medial to the autonomic nerves, as opposed to just peripheral to the mesorectum. Both sexual and urinary functions are complex. and patients undergoing surgery for rectal cancer may have differing baseline levels of function. Pre-existing benign prostatic hypertrophy or stress incontinence are common physical conditions. Patients bring personal or cultural attitudes to the subject of sexual function with advancing years. in a population with a median age in the mid-sixties. Other health issues such as coronary artery or peripheral vascular atherosclerotic disease, diabetes mellitus. smoking or alcohol intake, or the use of medications to treat these conditions, may influence sexual function. Radiation therapy, frequently used in conjunction with chemotherapy in the treatment of rectal cancer, may be associated with its own incidence of impotence caused via a different mechanism. While radiation may affect the vasa nervosa of the autonomic nerves, leading to fibrosis and dysfunction. radiation therapy may also be associated with smooth muscle fibrosis, causing vasculogenic impotence due to penile outflow dysfunction in the corpora cavernosa. The causes of impotence after surgery alone or after surgery. radiation, and chemotherapy for rectal cancer are complex, and not all answers to the problem reside in autonomic nerve-preservation. Attention to all of the potential causes of impotence and of urinary dysfunction will require continued longitudinal research by clinical investigators from multiple disciplines.

Experience of surgery for rectal cancer with total mesorectal excision in a general surgical practice

BACKGROUND

Results from specialist centres have shown that total mesorectal excision (TME) produces excellent control of local disease in patients with carcinoma of the rectum.

METHODS

The results of TME were reviewed in a surgical practice in which patients with rectal cancer comprised 1 per cent of the total caseload and mean case numbers were less than 15 each year.

RESULTS

Eighty-two consecutive patients underwent rectal excision with TME over a 72-month period (68 anterior resection, eight abdominoperineal excision and six Hartmann's procedure). Sixty-nine operations were deemed 'curative' at the time of surgery. Anastomotic leak occurred in two (3 per cent) of 68 patients, both of whom recovered without additional surgery. There were two local recurrences (3 per cent) among 69 patients who underwent 'curative' surgery. At a median follow-up of 190 weeks, the survival rate for Dukes' stage A, B, C and 'D' was 100, 83, 68 and 18 per cent respectively.

CONCLUSION

Outcome as measured by perioperative morbidity and local disease control achieved in a surgical practice with a broad case mix and relatively low annual case volume was comparable to that from larger centres. Appropriate surgical training and attention to technical detail may be as important as case volume in determining outcome after surgery for rectal cancer.

Lateral ligament: its anatomy and clinical importance

Since Miles proposed abdominoperineal excision as a radical surgery for rectal cancer in 1908, surgeons have recognized the lateral ligament in the pararectal space of their patients and attached clinical importance to it, although anatomists did not describe any such configuration in cadavers. By analyzing an experience of 421 lower rectal cancer cases at the Cancer Institute Hospital in Tokyo, discussion of the lateral ligament was focused on its relationship to the fascial arrangements in the pelvis, the pelvic autonomic nervous system, and the lymphatic drainage of the rectum. The lateral ligament is not an anatomical term, but a clinical or surgical one. It exists in a living pelvis as a condensation of connective tissue around the middle rectal artery and is divided into two segments by the inferior hypogastric nerve plexus inside it and the visceral endopelvic fascia around it. The lateral ligament is a pathway of blood vessels and nerve fibers toward the rectum and lymphatic vessels from the lower rectum toward the iliac lymph nodes. Therefore, the lateral ligament plays a critical role in surgery for lower rectal cancer in two respects: the anatomic extent of resection for curing rectal cancer, and the preservation of sexual function.

Current status of total mesorectal excision and autonomic nerve preservation in rectal cancer

Two decades have passed since the late 1970s, which witnessed the introduction of total mesorectal excision (TME)-based operations for rectal cancers on both sides of the Atlantic. Since the introduction of TME, clinical experience has been reported widely in the form of single- and multisurgeon reports from wide geographic regions with multiple participants, and from specialty services with narrow focus and high levels of expertise. All of these published results conclude that in comparison with conventionally practiced blunt surgery for rectal cancer, TME-based (i.e., anatomically correct, sharply performed) operations are associated with significantly lower rates of pelvic (local) recurrences, a significantly higher rate of survival, and significantly lower long-term morbidity. The latter is accomplished through dramatically higher rates of sphincter preservation, and the preservation of both sexual and urinary functions. Overall, there is a remarkable similarity in the clinical results that have been reported from diverse centers. TME now forms the basis of large randomized clinical trials in which the role of adjuvant therapy is being reexamined. The current status of TME is reviewed, and the authors' clinical results of a consecutive series of 544 TME-based operations performed through 1998 are updated.

Management of locally advanced rectal cancer

The treatment of rectal cancer typically involves a multidisciplinary approach. A minority of patients will have tumors that are full thickness, involve adjacent structures, or have metastatic disease to regional lymph nodes. The combination of adjuvant therapy and surgical resection is the mainstay of treatment for locally advanced carcinoma of the rectum. This article will review the role of adjuvant chemotherapy and radiotherapy in patients with high risk tumors. The operative considerations in advanced rectal cancers will be reviewed. In particular, the role of mesorectal excision and exenterative surgery will be discussed.