In this extensive review of the literature, Weber and Petrelli have nicely placed into perspective and documented the methods used in and results of most of the studies on local excision for rectal cancer. Although I agree with many of their conclusions, it is difficult for me to agree with the title of their article, "Local excision for rectal cancer: An uncertain future."
As outlined in the article by Biggers et al, only a minority of patients with rectal cancer benefit from a radical approach. Increasingly, the goal of todays surgeon is to tailor treatment to the extent of disease. As the authors point out, patients with T1 disease are generally well treated by local excision.
Follow-up and Survival
Fundamental to the evaluation of surgical management, however, is subsequent follow-up. Many articles do not document how patients are being followed. The study by Biggers et al reports that appropriate type and length of follow-up will show that approximately 20% of patients will develop a recurrence, but that most of these individuals will die of something unrelated to their cancer or its treatment. Thus, careful follow-up is generally associated with early identification of disease recurrence and successful subsequent management. In the review by Graham et al, in which follow-up was shown to be less precise and meticulous, cancer-related deaths were reported in 11% of patients.
The authors point out further that the role of adjuvant radiation therapy is less clear. Evidence from other adjuvant trials demonstrates that radiation therapy should help improve local control and may even enhance survival. The literature is somewhat confusing, however, as to whether preoperative or postoperative therapy would be more successful.
Preoperative staging is desirable. Ultrasound helps determine the depth of invasion, but no currently available techniques are helpful for predicting lymph node involvement. Several studies point to nuclear markers, such as the DCC gene or P53 gene, or to flow cytometry as being useful in predicting regional involvement. We find histologic and genetic studies to be important in the local management of patients with rectal cancer.
Designing a Treatment Plan
How, then, can one incorporate this myriad of information into a therapeutic strategy? We view the local management of rectal cancer as a staging procedure. In patients who have morphologic features suggesting that local management is possible (less than 3 cm of moderately to well-differentiated tumor), we favor local excision--ie, a full-thickness excision to allow for pathologic evaluation. We then subject the excised tissue to genetic analysis, including studies for P53 and DCC, as well as flow cytometry. If the analyses suggest unfavorable features, we recommend additional therapy. Also, if there is evidence of venous invasion or a T2-3 level of invasion, again, additional therapy should be discussed. However, if the results are favorable, no treatment beyond local excision is recommended.
When considering additional therapy, we feel that lymphadenectomy is the only proven treatment. Radiation therapy, although a sensible alternative, has not demonstrated effectiveness. Furthermore, as Biggers et al report, most patients will not benefit from a lymphadenectomy; thus, they need to be actively involved in the decision-making process regarding their treatment plan. A thoughtful, careful dialogue between the patient and physician is essential so that the patient understands that all treatments have risks, and that the success of any treatment cannot be uniformly predicted.