During the 1980s, the only drug routinely used to treat colorectal carcinoma was single-agent fluorouracil (5-FU), a drug that had shown no proven benefit in the adjuvant setting. Since then, significant improvements in the overall management of colorectal cancer have been made. This review will compare today's standard of care for adjuvant colorectal carcinoma to that practiced 20 years ago. The authors examine key questions asked about adjuvant therapy and the answers that ultimately changed clinical practice standards and improved overall survival for patients diagnosed with this disease. In addition, this review explores whether 5-FU should be given as part of a multidrug regimen and which route of administration is best when this drug is given. Further, the authors delve into both the use of locally directed therapies to the liver or peritoneum to improve outcomes and the selection of patients to receive adjuvant chemotherapy. Finally, a look to the future shows monoclonal antibodies to be an avenue of great promise in fighting colorectal cancer.
Advances in the treatment of
metastatic colorectal cancer in
the past several years have
been expeditious and exciting—even
chaotic—but with the median survival
doubled since the use of single-agent
fluoropyrimidines alone. However, new
questions continue to arise, directly affecting
our daily practice in the care of
patients with colorectal cancer. One of
these issues, the optimal therapy for
metastatic colorectal cancer, is wonderfully
explored by Dr. Saltz in this
issue of ONCOLOGY. To understand
this issue better, we may have to approach
the question a little differently:
That is, is it possible to standardize
treatment options for metastatic colorectal
From the results of recent studies, it is likely that multimodality
therapy with chemotherapy and radiation treatment may improve the
overall outcome of locally advanced upper gastrointestinal (GI) malignancies,
including esophageal, gastric, pancreatic, and biliary tract carcinomas.
However, more effective, more optimal, and less toxic chemotherapy
regimen(s) with concomitant radiotherapy are needed beyond
the concurrent continuous-infusion fluorouracil (5-FU) with radiation
that is commonly applied in general practice. Epirubicin (Ellence),
cisplatin, and irinotecan (Camptosar) are all active cytotoxic chemotherapy
agents in upper GI cancers. Two phase I studies were designed
to test the tolerability of the combination of radiotherapy with infusional
5-FU, epirubicin, and cisplatin (ECF) or 5-FU, irinotecan, and
epirubicin (EIF) in the treatment of locally advanced upper GI malignancies.
It is a continuing challenge for oncologists to effectively treat
advanced/metastatic pancreatic and biliary cancer. Both irinotecan
(CPT-11, Camptosar) and gemcitabine (Gemzar) have shown activity
against these diseases with different mechanisms. Preclinical and
clinical data also suggest additive or synergistic effects of the combination
of these two agents with few or no overlapping toxicities. Phosphorylation
of gemcitabine, a process of intracellular activation of the
agent, is dose-rate dependent. It has been suggested that the fixed-doserate
infusion of gemcitabine increases the concentration of intracellular
triphosphate gemcitabine, which in turn may result in more objective
responses and longer median survival compared to the standard infusion.
This phase I study tests the toxicity of the combination of irinotecan
with fixed-dose-rate infusion of gemcitabine, and determines the
dose of the combination for phase II investigation.
The role of sentinel lymph node identification has been investigated over the past decade in a variety of malignancies. It has become part of standard care for melanoma. Its role in breast cancer is evolving, but with the completion of two large randomized clinical trials, it will probably be added to the surgical armamentarium for the management of most breast cancers. Studies have been proposed or are under way to evaluate sentinel node mapping in head and neck cancer, penile and vulvar cancer, and gastrointestinal cancers.
The article by Drs. Khayat and Gil-Delgado outlines the exciting new developments in the treatment of advanced colorectal cancer with irinotecan (CPT-11 [Camptosar]) and oxaliplatin. Although the development of these drugs provides an alternative to fluorouracil (5-FU) in the treatment of this common tumor, it is still unclear how to optimally integrate these promising compounds into therapy for colorectal cancer.
UFT and leucovorin (Orzel) is a combination of tegafur and uracil in a molar ratio of 1:4. Tegafur, a prodrug of 5-fluorouracil (5-FU), is converted to 5-FU by the hepatic cytochrome P450 pathway, whereas uracil enhances the
Postoperative combined-modality therapy with fluorouracil (5-FU) and radiation therapy is accepted practice for high-risk rectal cancer. Postoperative pelvic radiotherapy alone may improve pelvic control, but is not associated with an improvement in survival.