Impact of overall treatment time on survival and local control in patients with anal cancer: a pooled data analysis of Radiation Therapy Oncology Group trials 87-04 and 98-11.

Abstract

PURPOSE:

To determine whether increased duration of radiation therapy (RT) and overall treatment (RX) time has a detrimental effect in anal cancer.

PATIENTS AND METHODS:

Data from Radiation Therapy Oncology Group (RTOG) 87-04 and RTOG 98-11 trials were combined to form three treatment groups: RT/fluorouracil (FU)/mitomycin (n = 472), RT/FU/cisplatin (n = 320), and RT/FU (n = 145). Cox proportional hazards models were used with the following variables: RT duration, RT intensity, RX duration, treatment group, age, sex, Karnofsky performance score (KPS), T stage, N stage, and RT dose.

RESULTS:

In the univariate analysis, there was a significant association between RX duration and colostomy failure (CF; hazard ratio [HR] = 1.51; 95% CI, 1.07 to 2.14; P = .02), local failure (HR = 1.52; 95% CI, 1.14 to 2.03; P = .005), locoregional failure (HR = 1.51; 95% CI, 1.15 to 1.98; P = .003), and time to failure (HR = 1.40; 95% CI, 1.10 to 1.79; P = .007). The significance of RX duration was maintained after adjusting for treatment group. In multivariate modeling there was a trend toward an association between RX duration and CF (HR = 1.57; 95% CI, 0.98 to 2.50; P = .06) and a statistically significant association with local failure (HR = 1.96; 95% CI, 1.34 to 2.87; P = .0006). Age, sex, KPS, T stage, N stage, and RT dose, but not RT duration, RT intensity, or RX duration, were found to be statistically significant predictors of OS and colostomy-free survival.

CONCLUSION:

Total treatment time, but not duration of radiation therapy, seems to have a detrimental effect on local failure and colostomy rate in anal cancer. Induction chemotherapy may contribute to local failure by increasing total treatment time.

• Authors: Edgar Ben-Josef, Jennifer Moughan, Jaffer A Ajani, Marshall Flam, Leonard Gunderson, JonDavid Pollock, Robert Myerson, Rani Anne, Seth A Rosenthal, Christopher Willett
• Journal: Journal of clinical oncology : official journal of the American Society of Clinical Oncology (J Clin Oncol) Vol. 28 Issue 34 Pg. 5061-6 (Dec 01 2010) ISSN: 1527-7755 [Electronic] United States
• PMID: 20956625 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Antineoplastic Agents
• Mitomycin
• Cisplatin
• Fluorouracil

Topics

• Antineoplastic Agents (administration & dosage)
• Anus Neoplasms (drug therapy, mortality, radiotherapy)
• Cisplatin (administration & dosage)
• Clinical Trials as Topic
• Combined Modality Therapy
• Female
• Fluorouracil (therapeutic use)
• Humans
• Male
• Mitomycin (administration & dosage)
• Proportional Hazards Models
• Radiotherapy (methods)
• Radiotherapy Dosage
• Time Factors