The 1993–94 patterns of care process survey for breast irradiation after breast-conserving surgery—comparison with the 1992 standard for breast conservation treatment

Abstract

Purpose: To determine the patterns of evaluation and treatment in the U.S. of women with early breast cancer treated with breast-conserving surgery and irradiation in 1993–94, and to compare these with a similar survey in 1983 and with the 1992 Standard for Breast Conservation Treatment. Methods and Materials: In 1995–96, 727 randomly selected records of eligible patients treated from 1993–94 at 62 facilities representative of 3 practice types were reviewed. Results: Compared with the Process Survey (PS) in 1983, patients in the 1993–94 study had an older age distribution. In the current study, 70% of patients were ≥ 50 years of age, and 69% were post-menopausal, compared with 59% ≥ 50 years of age and 49% post-menopausal in 1983 ( p = 0.0087 and < 0.001, respectively). Work-up and evaluation in the 1993–94 PS were closely aligned with the standard and were considerably improved compared with 1983. In the 1983 study, 77% of patients underwent mammography, as compared to 97% in the 1993–94 study. In 1983, pathological size documentation was performed in 83% of patients; in 1993–94, this was performed in 95% of patients. An estrogen receptor evaluation was performed in 36% of patients in 1983; in 1993–94, that increased to 76%. In 1983, 28% of patients underwent progesterone receptor evaluation; in 1993–94, this increased to 72%. Only 3% of patients in 1993–94 were enrolled in a clinical trial. Radiation treatment parameters closely adhered to standard recommendations, improving substantially from 1983. In 1983, wedge or compensator use was recommended for 64% of patients; in 1993–94, for 95% of patients. In 1983, 4–8 MV photons were recommended for breast treatment in 67% of patients; in 1993–94, 90%. In 1983, bolus was avoided in 75% of patients; in 1993–94, in 94%. In 1983, the recommended breast dose for 89% of patients was 45–50 Gy (44–51 Gy in PS); in 1993–94 this had increased to 99% of patients. In 1983, electrons were recommended for primary site boost in 70% of patients; in 1993–94, for 94% of patients. Conclusion: There was an extensive shift to adherence to the 1992 standard in 1993–94, compared with the 1983 PS, although there is room for improvement in some areas.