Carolyn Ferree

BACKGROUND: Adjuvant chemotherapy is widely used for breast cancer and is known to extend survival. Some clinicians seek a greater survival benefit by increasing the intensity of the dose, whereas others lower it to diminish toxicity. METHODS: The Cancer and Leukemia Group B (CALGB) conducted a randomized trial of different levels of doses and dose intensity (dose per unit of time) of adjuvant chemotherapy in 1572 women with node-positive, stage II breast cancer who were assigned to three treatment groups. One group received 400 mg of cyclophosphamide per square meter of body-surface area and 40 mg of doxorubicin per square meter once every 28 days and 400 mg of fluorouracil per square meter twice every 28 days, for six cycles. Another group received 50 percent higher doses of the three drugs (600 mg, 60 mg, and 600 mg, respectively) but for only four cycles, so that the total dose was identical in these two groups but the dose intensity was higher in the first. The third group of women received half the total dose used in the other two groups and at half the dose intensity used in the second group. RESULTS: After a median of 3.4 years of follow-up, the women treated with a high or moderate dose intensity had significantly longer disease-free survival (P < 0.001) and overall survival (P = 0.004) than those treated with a low dose intensity, in three-way log-rank comparisons. However, the difference in survival between the two groups treated with a moderate or high dose intensity was not significant. These results are consistent with either a dose-response effect or a threshold level of the dose or dose intensity. CONCLUSIONS: The doses of chemotherapy used to treat breast cancer, especially early breast cancer, should not be reduced if the maximal benefit is to be achieved.

BACKGROUND: Both total dose and dose intensity of adjuvant chemotherapy are postulated to be important variables in the outcome for patients with operable breast cancer. The Cancer and Leukemia Group B study 8541 examined the effects of adjuvant treatment using conventional-range dose and dose intensity in female patients with stage II (axillary lymph node-positive) breast cancer. METHODS: Within 6 weeks of surgery (radical mastectomy, modified radical mastectomy, or lumpectomy), 1550 patients with unilateral breast cancer were randomly assigned to one of three treatment arms: high-, moderate-, or low-dose intensity. The patients received cyclophosphamide, doxorubicin, and 5-fluorouracil on day 1 of each chemotherapy cycle, with 5-fluorouracil administration repeated on day 8. The high-dose arm had twice the dose intensity and twice the drug dose as the low-dose arm. The moderate-dose arm had two thirds the dose intensity as the high-dose arm but the same total drug dose. Disease-free survival and overall survival were primary end points of the study. RESULTS: At a median follow-up of 9 years, disease-free survival and overall survival for patients on the moderate- and high-dose arms are superior to the corresponding survival measures for patients on the low-dose arm (two-sided P<.0001 and two-sided P = .004, respectively), with no difference in disease-free or overall survival between the moderate- and the high-dose arms. At 5 years, overall survival (average +/- standard error) is 79% +/- 2% for patients on the high-dose arm, 77% +/- 2% for the patients on the moderate-dose arm, and 72% +/- 2% for patients on the low-dose arm; disease-free survival is 66% +/- 2%, 61% +/- 2%, and 56% +/- 2%, respectively. CONCLUSION: Within the conventional dose range for this chemotherapy regimen, a higher dose is associated with better disease-free survival and overall survival.

The obstruction of the superior vena cava by tumor is recognized as an acute or subacute oncologic emergency. Rapid high-dose irradiation to the mediastinum is shown to be effective therapy for a superior vena caval obstruction. In our series 35 patients have been treated with rapid high-dose irradiation between January 1971 and July 1977. The present treatment consists of 400 rad given in a daily midplane dose for 3 days, and then slowing to 150 rad mid-plane per day to a total dose of 3000 rad over 15 fractions. There have been no instances of exacerbations of symptoms or severe complications from this treatment. There have been 2 failures of the 35 patients treated with this regimen. Both were shown at autopsy to have massive thrombi obstructing the superior vena cava. Six years of experience using this regimen has proven to be a safe and effective means of treatment for superior vena caval obstruction. Cancer 42:2600–2603, 1978.

To determine if 6 courses of chemotherapy alone could achieve the same or better outcome than 4 courses of chemotherapy followed by radiation therapy (chemoradiotherapy) in pediatric and adolescent patients with Hodgkin disease. Children < or =21 years old with biopsy-proven, pathologically staged I, IIA, or IIIA1 Hodgkin disease were randomly assigned 6 courses of alternating nitrogen mustard, oncovin, prednisone, and procarbazine/doxorubicin, bleomycin, vinblastine, and dacarbazine (treatment 1) or 4 courses of alternating nitrogen mustard, oncovin, prednisone, and procarbazine/doxorubicin, bleomycin, vinblastine, and dacarbazine +2550 cGy involved-field radiotherapy (treatment 2). The complete response rate was 89%, with a complete response and partial response rate of 99.4%. There was no statistically significant difference in event-free survival (EFS) or overall survival between arms. The EFS for those who achieved an early complete response was significantly higher than for those who did not. For pediatric patients with asymptomatic low-stage and intermediate-stage Hodgkin disease, chemotherapy and chemoradiotherapy both resulted in 3-year EFS of approximately 90% and statistically indistinguishable 8-year EFS and overall survival, without significant long-term toxicity. Early response to therapy was associated with higher EFS, a concept that has led to the Children's Oncology Group paradigm of response-based risk-adapted therapy for pediatric Hodgkin disease.

The treatment of a superior vena caval obstruction associated with a mediastinal mass is a true radiotherapeutic emergency. The heralding signs and symptoms and the morbidity of the syndrome justify beginning therapy before a pathologic diagnosis is established. In a series of 19 patients with superior vena cava syndrome, there was an excellent response to an initial high-dose course of irradiation, consisting of 400 rads midplane for 3 days, then reduced to conventional daily fractionation. It is concluded that rapid high-dose irradiation in the treatment of a superior vena cava syndrome is safe and effective.