[Rectal cancer. How much radiotherapy do surgery patients need?]

Radiotherapy for Colorectal Cancer: Current Standards and Future Perspectives

BACKGROUND

Multimodal treatment approaches are indispensable for patients with advanced-stage colorectal cancer. Radiotherapy has been established as essential part of perioperative concepts and was introduced as an option to face challenges such as local relapse or oligometastases.

METHODS

A literature review was performed to summarize evidence and current standards of radiotherapeutic concepts in the treatment of colorectal cancer.

RESULTS

For stage II/III rectal cancer, neoadjuvant radiotherapy is superior to adjuvant treatment. Two preoperative regimens have been established and are commonly used with different objectives: short-course radiotherapy (SC-RT) and long-course chemoradiotherapy (LC-CRT). Both reduce the risk of local relapse. Additionally, LC-CRT aims at downsizing the tumor to potentially reduce radicalness of surgery. There is increasing evidence that not all stage II/III rectal cancer patients need neoadjuvant irradiation but also that in some cases surgery might be omitted. Stereotactic body radiotherapy (SBRT) of the liver shows high rates of local control in oligometastatic patients. Intraoperative and particle radiotherapy extend the spectrum of treatment options for locally recurrent patients.

CONCLUSION

Radiotherapeutic concepts are crucial for the primary management of locally advanced colorectal cancer and can essentially contribute to treatment approaches in locally recurrent, oligometastatic or palliative patients.

[Radiotherapy-associated morbidity and mortality in rectal surgery]

The treatment of rectal cancer has evolved significantly in recent decades. Both modern radiotherapy treatment concepts and surgical techniques have been able to improve oncological as well as functional outcomes for rectal cancer patients. Large-scale, multicenter, randomized trials have been able to demonstrate the benefits of neoadjuvant treatment over adjuvant radiotherapy. In addition, local tumor control is improved by neoadjuvant irradiation. Conversely, patients receiving a total mesorectal excision showed no survival advantage following irradiation vs. only surgically resected patients. In addition, radiation therapy is associated with a certain morbidity and mortality. This paper summarizes the available evidence regarding postoperative morbidity, mortality, and long-term chronic effects of neoadjuvant radiotherapy.

MRI-based treatment of rectal cancer: is prognostication of the recurrence risk solid enough to render radiation redundant?

BACKGROUND

Most current guidelines recommend neoadjuvant short course radiotherapy (sRT) or radio-chemotherapy (nRCT) for rectal cancer stage II and III. After the introduction of total mesorectal excision (TME) and magnetic resonance imaging (MRI), this proceeding has been questioned and omission of neoadjuvant treatment according to preoperative MRI-criteria has been propagated. Aim of the present paper is to review the state of evidence regarding MRI-based treatment decision depending on the predicted width of the circumferential resection margin (CRM).

METHODS

A comprehensive survey of the literature was performed using the search terms "rectal cancer", "radiotherapy", "radio-chemotherapy", "MRI-based therapy", "circumferential resection margin". Data from lately published observational studies were compared to results from randomized trials and outcome analyses of the Norwegian national cancer registry.

RESULTS

Only one observational study using MRI-based treatment according to the anticipated CRM provided 5 year local recurrence data, however only for 65 patients. The second study did not yet evaluate recurrence rates. Two randomized trials comparing sRT to primary TME showed significantly worse outcome for non-irradiated patients. Data from the Norwegian rectal cancer registry demonstrate that TME alone is associated with higher LRR than achievable with preoperative RT.

CONCLUSIONS

Current evidence does not support the omission of neoadjuvant treatment for stage II-III rectal cancer on the basis of an MRI-predicted negative CRM. Randomized studies are warranted to clarify whether and for which subgroups TME alone is safe in terms of local recurrences.

Pelvic exenteration for advanced rectal cancer

SUMMARY Advanced rectal cancer is defined by local tumor invasion into adjacent structures and organs in the pelvis. A curative multimodal therapy approach for patients with advanced rectal cancer includes neoadjuvant treatment with subsequent pelvic exenteration. Pelvic exenteration is associated with high perioperative morbidity as this surgical procedure includes an extensive resection of pelvic anatomical planes with en bloc removal of the tumor and surrounding organs and structures. Safe reconstruction of the large pelvic floor defect is very important. Quality of life and oncological outcome after pelvic exenteration for advanced rectal cancer are good. In this article, we highlight important clinical and surgical aspects of pelvic exenteration for advanced rectal cancer and review the recent literature.

[Protective stoma after deep anterior rectal resection: pro]

There is still controversy about the necessity of a diverting stoma after deep anterior resection with total mesorectal excision for rectal cancer. Recent results of randomized controlled trials and from systematic reviews have improved the currently available data. A significant benefit was shown for patients with diverting stoma in terms of clinically relevant anastomotic leakage and re-operation rates. The influence on mortality is not as clear. However, analysis of the data of 19 prospective studies within a systematic review including more than 9,000 patients, revealed a significant benefit for stoma creation. Furthermore, the rate of patients with stoma 5 years after primary resection was lower in the group of patients with diverting stoma. The purpose of this manuscript is to show the necessity of a diverting stoma based on the currently available data.

Regional lymph node metastasis and locoregional recurrence of rectal carcinoma in the era of TME [corrected] surgery. Implications for treatment decisions

BACKGROUND AND AIMS

For rectal carcinoma treated according to the concept of total mesorectal excision (TME surgery), the independent influence of regional lymph node metastasis on the locoregional recurrence risk is still in discussion. A reliable assessment of this risk is important for an individualised selective indication for neoadjuvant radio-/radiochemotherapy.

METHODS

Analysis of literature, especially of the last 20 years, and consideration of pathological and oncological basic research. Multivariate analysis of data of the Erlangen Registry of Colorectal Carcinoma.

RESULTS

The clinical assessment of the pretherapeutic regional lymph node status by the present available imaging methods is still unreliable. The analysis of the association between pretherapeutic regional lymph node status and locoregional recurrence risk has to be based on follow-up data of patients treated by primary surgery and has to be distinguished between patients treated by conventional and optimised quality-assured TME surgery, respectively. Data from Erlangen show an increase of the local recurrence risk for patients with at least four involved regional lymph nodes.

CONCLUSIONS

For patients with at least four involved regional lymph nodes, a neoadjuvant radiochemotherapy may be indicated. However, today, the pretherapeutic diagnosis is uncertain and results in overtherapy in 40%. Thus, in case of positive lymph node findings by imaging methods, the benefits and risk of neoadjuvant therapy in such situations should always be discussed with the patient in the sense of informed consent and shared decision.