Outcomes of surveillance mammography after treatment of primary breast cancer: a population-based case series.

GOAL: To ascertain outcomes of surveillance mammography (SM) following treatment of early stage unilateral primary breast cancer (PBC) in a population based case series. METHODS: Random samples from all 12,279 women having breast surgery within 4 months after diagnosis of PBC, between July 1991 and December 1993 in Ontario, were drawn from a database created by deterministic linkage of PBC files from the Ontario Cancer Registry (OCR) with episodes of breast surgery extracted from the hospital Discharge Abstract Database (DAD), and mammography from the Ontario physician billings database (OHIP). Among women having >or=1 episode(s) of breast surgery subsequent (SBS) to the date of diagnosis up to December 2000, a sample of 1,200/5,064 (23.7%) was drawn, and among women with no SBS, a sample of 400/7,215 (5.5%). Among these two samples, operative, pathology, and mammography reports were abstracted from original charts. Treatments were abstracted and categorized. Women with complete data for Stages 1 and 2 unilateral PBC were included. From the subsequent surgery sample, 609/1,200 (50.8%) were excluded because of simultaneous or sequential bilateral breast cancers or mastectomies within 6 months, missing stage information, Stage 3 or 4 PBC, or missing primary charts. From the no subsequent surgery sample, 90/400 (22.5%) were excluded by the same criteria. Episodes of bilateral 2-view X-ray mammography, beginning >or=6 months after the diagnosis of unilateral PBC, and if multiple, at least 11 months apart, and not prompted by a clinical concern or symptom, were classified as SM. We confirmed episodes of cancer recurrence within the ipsilateral conserved breast (CRICB) and metachronous contralateral primary breast cancer (CPBC) >or=6 months after the diagnosis of the unilateral PBC from original operative and pathology reports. We used Cox models to describe the association of exposure to >or=1 episode(s) of SM with the risk of death from breast cancer among the study population, and separately among women experiencing CRICB or CPBC. RESULTS: Eligible women comprising 591/1,200 and 310/400 produced a combined case series of 901/1,600 (56.3%). Women with >or=1 episode(s) of SM numbered 721/901 (80.0%). We confirmed 84 CRICB events among 584 women initially treated by lumpectomy (14.4%), and 49 CPBC events among all 901 women in the study population (5.4%). Among women having >or=1 episode(s), the 25th percentile of observed follow up was 1,631 days, the 50th, 4,287 days, and the 75th 5,011 days. Among women without any SM, the 25th percentile of observed follow-up was 440 days, the 50th, 891 days, and the 75th, 1,849 days. Hazard ratio (HR) for death due to breast cancer associated with >or=1 episode of SM was 0.28 (95% CI 0.22-0.37), adjusted for age, stage, type of surgery, adjuvant chemotherapy, and tamoxifen. Among 84/584 women with CRICB, unadjusted HR = 0.36 (95%CI 0.13, 1.00) and among 49/901 women with CPBC, unadjusted HR = 0.86 (0.20-3.77). CONCLUSION: SM was associated with a significant reduction in the hazard for breast cancer death. Among women who experienced CRICB, the reduction was of borderline significance, and the reduction was not significant among women who experienced CPBC.

A population-based case-cohort study of the risk of myocardial infarction following radiation therapy for breast cancer.

OBJECTIVE: To describe the risk of acute myocardial infarction (AMI) after radiation therapy (RT) for breast cancer (BrCa) in an exposed population. METHODS: We identified and validated cases of AMI (vAMI), by electrocardiographic or enzyme criteria, among all 6680 women who received post-operative RT following lumpectomy or mastectomy, within 12 months following diagnosis of BrCa between 1982 and 1988 in Ontario, Canada. We identified women without vAMI whose death certification was ascribed to AMI (dAMI). We abstracted risk factors and treatment exposures for a random sample of women from the 6680, and for all with vAMI or dAMI. The hazards of vAMI and of dAMI were estimated using multivariate Cox proportional hazards models, corrected for study design. RESULTS: We validated 121 cases of vAMI and identified 92 cases of dAMI. The risk of vAMI associated with RT to the left breast HR=1.96 (1.09,3.54) among women at age >/= 60 at time of RT, adjusted for history of smoking and prior MI. The adjusted HR dAMI=1.90 (1.08,3.35) for exposure to anterior internal mammary node (IMC) RT. Among women who received anterior left breast boost RT, increasing area of the boost is associated with adjusted HR vAMI=1.02 (1.00,1.03)/cm(2), and adjusted HR dAMI=1.02 (1.01,1.03)/cm(2). CONCLUSION: The risks of vAMI and dAMI following RT for BrCa are related to anatomic sites of RT (left breast, area of anterior left breast boost field, and anterior IMC field).

Waiting times for radiation therapy in Ontario.

BACKGROUND: The mass media and clinical journals have reported lengthy waiting times after surgery before initiation of radiation therapy (RT) for cancer across Canada. We aimed to describe the length of time between the last date of surgery or biopsy or chemotherapy and first date of RT. METHODS: This is a population-based study measuring waiting times for RT in Ontario among all patients with potentially curable cancer of the cervix, tonsil and larynx and a random sample of women who had had breast cancer resection, whose first date of RT fell between Sept. 1, 2001, and Aug. 31, 2002. Abstraction of original health care records provided each patient's demographics, cancer stage and cancer treatment (last surgery, consultation, simulation, first RT). Last dates of chemotherapy before RT were obtained from abstraction or from Ontario Health Insurance Plan (OHIP) files, and last dates of surgery before RT were compared with dates in the Canadian Institute for Health Information (CIHI) Discharge Abstract Database. RESULTS: Waiting times between the last date of surgery or chemotherapy and the first date of RT varied significantly among the health regions of Ontario. Increasing age, but not the presence of comorbidity, was associated with longer waiting times. Women who did not receive postoperative chemotherapy before RT for breast cancer waited significantly longer than all others. CONCLUSION: Measurement of waiting times for cancer RT must discount time during which adjuvant intravenous chemotherapy is administered after surgery and before RT. There appears to be a formal or informal process by which those at highest risk begin RT most rapidly.

Late radiation morbidity following randomization to preoperative versus postoperative radiotherapy in extremity soft tissue sarcoma.

BACKGROUND AND PURPOSE: This study compared late radiation morbidity in patients with extremity soft tissue sarcoma randomized to treatment by pre- (50 Gy) or postoperative (66 Gy) radiotherapy in combination with surgery. The morbidities evaluated included fibrosis, joint stiffness and edema at 2 years following treatment. The impact of morbidity on patient function as measured by the Musculoskeletal Tumor Rating Scale (MSTS) and the Toronto Extremity Salvage Score (TESS) was also evaluated. PATIENTS AND METHODS: 129 patients were evaluated. Toxicity rates were compared by treatment arm using the Fisher's exact test. Function scores by toxicity were analyzed using the Wilcoxon rank sum test. Multivariate logistic regression was used to evaluate the joint effect of treatment arm, field size, and dose on subcutaneous tissue fibrosis, joint stiffness and edema. RESULTS: 27 of 56 patients (48.2%) in the postoperative arm compared to 23 of 73 (31.5%) in the preoperative arm had grade 2 or greater fibrosis (P = 0.07). Although not statistically significant, edema was more frequent in the postoperative arm, 13 of 56 (23.2%) versus 11 of 73 (15.5%) in the preoperative arm, as was joint stiffness, 13 of 56 (23.2%) versus 13 of 73 (17.8%). Patients with significant fibrosis, joint stiffness or edema had significantly lower function scores on both measures (all P-values < 0.01). Field size was predictive of greater rates of fibrosis (P = 0.002) and joint stiffness (P = 0.006) and marginally predictive of edema (P = 0.06). CONCLUSIONS: Patients treated with postoperative radiotherapy tended to have greater fibrosis. Fibrosis, joint stiffness and edema adversely affect patient function.

Role of radiation therapy in patients with a diagnosis of both systemic lupus erythematosus and cancer.

OBJECTIVE: To determine whether radiation therapy (RT) is denied to patients with lupus and cancer and whether RT causes unusual toxicity in those receiving it. METHODS: We included patients with lupus followed at the University of Toronto Lupus Clinic between 1972 and 2001 who had developed cancer. Demographic, clinical, and laboratory information were collected prospectively. Pathologic proof of cancer was obtained. Three radiation oncologists blinded for the diagnosis of lupus, the modalities of cancer treatment, and the hypothesis of the study reviewed patient data independently. They assessed the indication for RT and whether it should be curative or symptomatic. Recommendation for RT was considered when at least 2 of the 3 radiation oncologists concurred. A review of the literature was conducted. RESULTS: Forty cases of cancer in 38 patients were identified. Most frequent cancer sites were breast (8), skin (8), digestive (7), and hematologic (7). Median patient age was 58 years. The radiation oncologists recommended RT in 26 cases, either with a curative (14) or a symptomatic intent (12). Only 4 patients received RT, 3 with a curative intent and 1 with a symptomatic intent. None of these 4 patients developed any unusual toxicity. The literature review did not support the fact that lupus patients do not tolerate RT. CONCLUSION: Sixty-five percent of our lupus patients with cancer could have received curative or symptomatic RT but only 10% received it. No patient developed any toxicity. RT may be inappropriately withheld from lupus patients with cancer.

Randomized trial of breast irradiation schedules after lumpectomy for women with lymph node-negative breast cancer.

BACKGROUND: Breast irradiation after lumpectomy is an integral component of breast-conserving therapy that reduces the local recurrence of breast cancer. Because an optimal fractionation schedule (radiation dose given in a specified number of fractions or treatment sessions over a defined time) for breast irradiation has not been uniformly accepted, we examined whether a 22-day fractionation schedule was as effective as the more traditional 35-day schedule in reducing recurrence. METHODS: Women with invasive breast cancer who were treated by lumpectomy and had pathologically clear resection margins and negative axillary lymph nodes were randomly assigned to receive whole breast irradiation of 42.5 Gy in 16 fractions over 22 days (short arm) or whole breast irradiation of 50 Gy in 25 fractions over 35 days (long arm). The primary outcome was local recurrence of invasive breast cancer in the treated breast. Secondary outcomes included cosmetic outcome, assessed with the European Organisation for Research and Treatment of Cancer (EORTC) Cosmetic Rating System. All statistical tests were two-sided. RESULTS: From April 1993 through September 1996, 1234 women were randomly assigned to treatment, 622 to the short arm and 612 to the long arm. Median follow-up was 69 months. Five-year local recurrence-free survival was 97.2% in the short arm and 96.8% in the long arm (absolute difference = 0.4%, 95% confidence interval [CI] = -1.5% to 2.4%). No difference in disease-free or overall survival rates was detected between study arms. The percentage of patients with an excellent or good global cosmetic outcome at 3 years was 76.8% in the short arm and 77.0% in the long arm; the corresponding data at 5 years were 76.8% and 77.4%, respectively (absolute difference = -0.6%, 95% CI = -6.5% to 5.5%). CONCLUSION: The more convenient 22-day fractionation schedule appears to be an acceptable alternative to the 35-day schedule.