Radiotherapy for rectal cancer

Radiotherapy in gastric cancer: a systematic review of literature and new perspectives

Gastric cancer is still a major problem for oncologists. Surgery is the main therapeutic approach; a complete surgical resection is usually necessary to offer potentially curative therapy to patients with adenocarcinoma of the stomach. However, many patients with more locally advanced tumors will experience local and distal recurrences. When a recurrence occurs, only palliative therapy is possible. In operable gastric cancer, both the extent of surgery and the value of adjuvant treatment remain subject to considerable international controversies. To improve local control, surgeons address the role of standardized surgery and of more extended surgery. Radiotherapy appears to improve local control and survival in the adjuvant arms, but perspective randomized trials are scarce and reported over many years. Retrospective experience demonstrated a low local recurrence rate, but was affected by large heterogeneity. However, evidence published in the last few years, improved radiotherapy technologies, better knowledge of the at-risk areas (enabling smaller radiotherapy volumes) and growing interest in neoadjuvant approaches support the role of radiotherapy in gastric cancer.

Effects of radiotherapy on different histopathological types of rectal carcinoma

BACKGROUND

Down staging by pre-operative chemoradiotherapy is currently considered part of the standard therapeutic approach to rectal carcinoma. The aim of this study was to assess the response to chemoradiotherapy of different histopathological types of rectal carcinoma with emphasis on the mucinous variant.

METHOD

Between 1997 and 2002, 71 patients who received pre-operative chemoradiotherapy followed by surgery for rectal carcinoma were enrolled in the study. Staging of the rectal carcinoma was performed according to transrectal ultrasound findings (TN score) prior to the chemoradiotherapy. The chemoradiotherapy was followed by radical resection with mesorectal excision. All surgical specimens were examined by a single pathologist (MB). Pathological TN staging was assessed and tumour regression was graded according to a standard method (TRG1, complete response - TRG5 no response). Tumours were classified as mucinous or nonmucinous according to pre- and post-operative biopsy and specimen histopathological types. TN score change and TRG differences between groups were assessed.

RESULTS

Tumour regression was seen after chemoradiotherapy in 94.4% of the patients, while in 5.6% of the patients no response was found. The change in TN score and TRG were correlated. Higher TRG was associated with a smaller decrease in TN staging. TRG was significantly lower in the nonmucinous compared to the mucinous group and the decrease in TN grade was significantly larger in the nonmucinous group.

CONCLUSION

Mucinous carcinoma was associated with a lower response to pre-operative chemo-radiotherapy in this group of rectal carcinoma patients. Further studies are needed to determine its prognostic value.

Endoscopic ultrasound for rectal cancer

The application of EUS has improved the way we evaluate and manage patients with rectal cancer. EUS has substantially greater sensitivity than CT in detecting advanced T stage tumors. Such improved sensitivity results in changes in preoperative therapy that would not otherwise have occurred without EUS. Although the addition of FNA provides little incremental effect on patient management, it carries the most potential for impacting management in those patients with early T stage disease, and its use should be considered in this subgroup of patients. Whether the accurate staging ability of EUS translates into improved outcomes in terms of reduced recurrence rates and ultimately prolonged survival remains uncertain. This will require further long-term outcome studies focusing on the endpoint of tumor recurrence and patient survival.

A prospective, blinded assessment of the impact of preoperative staging on the management of rectal cancer

BACKGROUND & AIMS

The influence of preoperative staging of rectal carcinoma on therapeutic decisions is uncertain. The use of fine-needle aspiration (FNA) of perirectal nodes in this setting has not been evaluated. The aim of this prospective, blinded study of patients with rectal cancer was to assess the impact of preoperative staging on treatment decisions and compare the tumor (T), nodal (N) staging performance characteristics of pelvic computed tomography (CT), rectal endoscopic ultrasonography (EUS), and EUS FNA.

METHODS

Eighty consecutive patients with newly diagnosed rectal cancer were prospectively evaluated. Therapy decisions were recorded after sequential disclosure of staging information to the patient's surgeon.

RESULTS

In 31% of patients (95% confidence interval, 21%-42%), EUS staging information changed the surgeon's original treatment plan based on CT alone. The further addition of FNA changed therapy in one patient. T staging accuracy was 71% (CT) and 91% (EUS) (P = 0.02); N staging accuracy was 76% (CT), 82% (EUS), and 76% (EUS FNA) (P = NS).

CONCLUSIONS

Preoperative staging with EUS results in more frequent use of preoperative neoadjuvant therapy than if staging was performed with CT alone. The addition of FNA only changed the management of one patient, whereas FNA did not significantly improve N staging accuracy over EUS alone. FNA seems to offer the most potential for impacting management in those patients with early T stage disease, and its use should be confined to this subgroup of patients. EUS is more accurate than CT for determining T stage of rectal carcinoma.