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Biomedical subjects

L J Mahoney

Publications and source records attributed to L J Mahoney.

At least 19 recordsLinked to original sources
PubMed1996

Randomized clinical trial of breast irradiation following lumpectomy and axillary dissection for node-negative breast cancer: an update. Ontario Clinical Oncology Group.

BACKGROUND: Breast-conservation surgery is now commonly used to treat breast cancer. Postoperative breast irradiation reduces cancer recurrence in the breast. There is still controversy concerning the necessity of irradiation of the breast in all patients. PURPOSE: We present an update of results from a randomized clinical trial designed to examine the efficacy of breast irradiation following conservation surgery in the treatment of women with axillary lymph node-negative breast cancer. The patients were enrolled from April 1984 through February 1989. Initial results were published in 1992 after a median follow-up time of 43 months. It was reported that recurrence of cancer in the breast occurred in 5.5% of the patients who received breast irradiation compared with 25.7% of those who did not. No difference in survival was detected between the two treatment groups. Now that the median patient follow-up has reached 7.6 years, the trial end points have been re-examined and an attempt has again been made to identify a group of patients at low risk for recurrence of cancer in the breast. METHODS: Eight hundred thirty-seven patients with node-negative breast cancer were randomly assigned to receive either radiation therapy (n = 416) or no radiation therapy (n = 421) following lumpectomy and axillary lymph node dissection. The cumulative local recurrence rate as a first event, distant recurrence (i.e., occurrence of metastasis) rate, and overall mortality rate for the treatment groups were described by the Kaplan-Meier method and compared with the use of the logrank test. The Cox proportional hazards model was used to adjust the observed treatment effect for the influence of various prognostic factors (patient age, tumor size, estrogen receptor level, and tumor histology) at study entry on the outcomes of local breast recurrence, distant recurrence, and overall mortality. All P values resulted from the use of two-tailed statistical tests. RESULTS: One hundred forty eight (35%) of the nonirradiated patients and 47 (11%) of the irradiated patients developed recurrent cancer in the breast (relative risk for patients in the former versus the latter group = 4.0; 95% confidence interval = 2.83-5.65; P < .0001). Ninety-nine (24%) of the patients in the former group have died compared with 87 (21%) in the latter group. Age (< 50 years), tumor size (> 2 cm), and tumor nuclear grade (poor) continued to be important predictors for local breast relapse. On the basis of these factors, we were unable to identify a subgroup of patients with a very low risk for local breast cancer recurrence. Tumor nuclear grade, as previously reported, and tumor size were important predictors for mortality. CONCLUSIONS: Breast irradiation was shown to reduce cancer recurrence in the breast, but there was no statistically significant reduction in mortality. A subgroup of patients with a very low risk for local breast recurrence who might not require radiation therapy was not identified.

Adult↗
PubMed1994

Screening mammography: interpretation of the data.

The literature on screening mammography includes a plethora of conflicting articles. More recently, individuals and various medical organizations have recommended and established their own guidelines for screening mammography. A review of salient breast screening randomized clinical trials in women over and under the age of 50 years is provided and compared with the more recent results of the Canadian National Breast Screening Study. In women under the age of 50 years, screening mammography cannot be supported from the results of these trials. In women over the age of 50 years, screening mammography leads to a significant reduction in breast cancer mortality and should be strongly recommended.

Adult↗
PubMed1992

Randomized clinical trial to assess the effectiveness of breast irradiation following lumpectomy and axillary dissection for node-negative breast cancer.

BACKGROUND: Although the conservation management of breast cancer has become a routine method of treatment in most centers, there is still considerable controversy surrounding the ultimate minimum treatment required for node-negative breast cancer to achieve adequate local control. PURPOSE: Our purpose was to assess the value of breast irradiation in reducing breast relapse following conservation surgery for node-negative breast cancer. We attempted to define low-risk groups of women for breast and distant site relapse (i.e., recurrence outside the breast) who might be spared breast irradiation or adjuvant systemic therapy. METHODS: Eight hundred thirty-seven patients were randomly assigned to receive radiation therapy or no radiation therapy following lumpectomy and axillary dissection for node-negative breast cancer. RESULTS: Breast irradiation reduced relapse in the breast from 25.7% in the controls to 5.5% in the irradiated patients. There was no difference in survival between the two groups (median follow-up, 43 months). A low-risk group (less than 5% chance of relapse in the breast without irradiation) could not be defined. Tumor size (greater than 2 cm), age (less than 40 years), and poor nuclear grade were important predictors for breast relapse. Age (less than 50 years) and poor nuclear grade were important predictors for mortality. The presence of ductal carcinoma in situ did not predict breast relapse. CONCLUSIONS: Breast irradiation significantly reduces breast relapse, but it does not influence survival. Important predictors of breast relapse are age, tumor size, and nuclear grade, but not the presence of ductal carcinoma in situ. Age and, in particular, nuclear grade predict survival. IMPLICATIONS: Further follow-up may define an acceptable low-risk group for breast relapse. Until then, we recommend that all patients receive breast irradiation. Systemic adjuvant therapy should be considered for patients with poor nuclear grade tumors.

Age Factors↗
PubMed1992

Reasons for non-entry in randomized clinical trials for breast cancer: a single institutional study.

Reasons for patient non-entry in randomized clinical trials (RCTs) assessing oncologic treatment modalities are not well documented in the literature. We have prospectively recorded reasons for RCT non-entry in breast cancer patients at St. Michael's Hospital, Toronto. From September 1984 to November 1989, 592 consecutive patients were evaluated through the clinical trials office. One hundred six out of the 592 patients were placed into a RCT (17.9%). Protocol ineligibilities accounted for 273 non-entries (46.1%) and protocol eligible but not entered patients accounted for 213 (36.0%) non-entries. The most common reason for protocol ineligibility was advanced age (94 patients). The most common reason for protocol eligible but not entered patients was patient refusal (148 patients). A total of 272 patients in both non-entered groups were identified as having reasons for non-entry that were potentially correctable. In summary, protocol ineligibilities account for the majority of non-entered patients, but patient refusal accounted for the single largest group of potentially correctable non-entries. More dissemination about the merit of RCTs in the lay press and amongst primary care physicians must take place if we are to expediently and efficiently answer important oncologic questions.

Breast Neoplasms↗
PubMed1985

Adenocarcinoma and colitis cystica profunda in a radiation-induced colonic stricture.

A case of adenocarcinoma of the rectum occurring 17 years after pelvic irradiation for squamous carcinoma of the cervix is reported. Earlier colonic resection had shown localized colitis cystica profunda in a radiation-induced colonic stricture. Colorectal cancer is an infrequent sequel to radiotherapy, which may occur many years after treatment of the primary tumor. Prolonged follow-up of these patients is essential.

Adenocarcinoma↗
PubMed1983

Predicting nodal metastases in breast cancer by lymphoscintigraphy.

In a prospective trial, 89 women with breast lumps underwent bilateral axillary and internal mammary lymphoscintigraphy preoperatively, using technetium-99m antimony sulfide colloid. All scans were interpreted blindly by three separate observers. Breast biopsy was then performed; if the biopsy specimen showed malignant tumour, definitive therapy was performed with axillary dissection. The interpretation of the axillary and internal mammary lymphoscintigrams was subsequently compared with the histologic assessment of the axillary nodes. Of the 89 women, 54 had benign disease and 35 had cancer. The internal mammary lymphoscintigram was considered to show abnormality in only 1 of the 54 patients with benign disease. One patient with cancer was eliminated from the review. Sixteen of the remaining 34 patients had axillary node metastases. Of these, 8 had an abnormal internal mammary lymphoscintigram. Only 2 of the 18 patients with cancer but no axillary metastases had an abnormal internal mammary lymphoscintigram. One bilateral axillary lymphoscintigram in the 54 patients with benign disease was discarded for technical reasons. The axillary lymphoscintigram was accurate in 52 of the remaining 53 patients. Two such scintigrams in the 35 patients with breast cancer were discarded for technical reasons. The axillary lymphoscintigram indicated abnormalities in 12 of 16 patients with axillary nodal metastases but appeared normal in 13 of 17 patients without axillary metastases. Lymphoscintigraphy may play a valuable role in the staging of breast cancer in the future.

Antimony↗
PubMed1982

Breast cancer: a 21 year experience with conservative surgery and radiation.

Evidence is presented from a study of 680 patients followed over a period of 21 years that conservative treatment of breast cancer by local excision of the primary tumor followed by breast irradiation yields results equivalent to the traditional radical approach, with the added benefit of an excellent cosmetic result and improved quality of life. The relative survivals were 8.3% at 5 years and 71% at 10 years. There was no difference in survival when radiation was given. Breast irradiation significantly reduced relapse in the breast, but axillary irradiation did not influence relapse at this site. Relapse in the breast alone was not detrimental to survival if treated appropriately. Axillary relapse indicated a much poorer prognosis as might be expected.

Brain Neoplasms↗
PubMed1977

Early diagnosis of breast cancer: experience in a consultant breast clinic.

Of 2839 women referred to a consultant breast clinic for clinical, mammographic and thermographic examination, 480 underwent biopsy and 126 were found to have cancer. Ten percent of the tumours were occult and were classified as very early biologic disease; they were identified by routine mammography in women whose breasts were clinically normal. Biopsy of solid mass lesions non-suspicious on mammography identified 20% of the cancers; half these lesions, classified as early biologic disease, were discovered by doctors at routine annual clinical breast examination, though the earliest cancers were detected by women who were confident and competent in monthly self-examination of the breasts. Biopsy of solid mass lesions suspicious on mammography identified 70% of the cancers; these were classified as late biologic disease. Skin or nipple dimpling or retraction was evident in two thirds of the patients; their lesions seemed to be later biologically than the lesions of the patients without clinical signs, and 75% had discovered the lesions themselves accidentally.

Adult↗
PubMed1977

Preoperative irradiation in operable cancer of the rectum: report of the Toronto trial.

The authors have studied the value of preoperative radiotherapy in 125 patients with cancer of the rectum. The patients were divided into two groups, control (no irradiation) and experimental (irradiation), and according to Dukes' pathological stage. The crude survival indicated no difference between the two groups, but analysis by stage and group demonstrated that for patients with a Dukes' stage C lesion, 500 rads of cobalt-60 gamma irradiation a few hours before excision of the lesion approximately doubles the probability of survival at 5 years. The prospect of surgical cure is three times higher in cancers arising above the peritoneal reflection than in those arising below it. If the practice of abdominoperineal resection is to continue the authors recommend that preoperative irradiation become a routine procedure.

Adenocarcinoma↗
PubMed1976

Use of the thermography for the early diagnosis of deep vein thrombosis following hip operations.

Up to 50% of patients suffer from deep vein thrombosis (DVT) after major hip surgery. Frequently DVT cannot be diagnosed clinically. To the present, venography alone has been used in these patients, but it is time consuming, necessitates an intravenous dye injection and is not without complications. Now, however, the technique of thermography is available as an additional diagnostic aid. The results of thermography were assessed in 24 patients who had recently undergone major hip operations and compared with those obtained by venography. Thermography did identify DVT in the lower leg veins of patients with no clinical symptoms, but higher obstructions were only diagnosed by venography. Thermography gave one false-positive result later disproven by venography. Thermography has the advantage of being noninvasive and economical; it will become more useful when smaller portable systems are developed.

Aged↗