Whole-breast irradiation, as part of breast-conservation therapy (BCT), has well-established results, good cosmesis, and low toxicity. Results from the BCT trials suggest that the risk for ipsilateral breast cancer recurrence resides within close proximity to the original tumor site. This leads investigators to consider the role of an accelerated and more tumor bed-focused course of radiotherapy. Accelerated partial-breast irradiation (APBI) involves treating a limited volume of breast tissue, with dose of irradiation per fraction increased and the treatment time course decreased. Four currently available methods of APBI are interstitial brachytherapy, intracavitary brachytherapy, intraoperative radiotherapy, and three-dimensional conformal external-beam radiotherapy. Patient selection is critical. This review article presents some preliminary clinical observations and limitations that suggest a potential role for APBI as a more user-friendly mode for delivering radiotherapy after lumpectomy for early breast cancer.
ObjectiveTo determine the compliance with a standard breast-conservation therapy (BCT) program in a predominantly indigent, minority population of patients with early breast cancer (stage I and II) served by a rural state institution in the South; to compare the clinical outcomes of this group with those reported in clinical trials; and to examine the socioeconomic factors that may have contributed to the rate of compliance. Summary Background DataDisease-free survival and overall survival in early breast cancer treated by BCT versus modified radical mastectomy are reported to be equivalent in prospective randomized trials. However, patients enrolled in clinical trials may not be representative of patients living in the various diverse communities that make up the United States. The authors' hypothesis is that patients enrolled in clinical trials at the national level may not be representative of indigent patients in the rural South and that clinical trial results may not be directly applicable. MethodsA retrospective review of 55 women with early-stage breast cancer treated from 1990 to 1995 was performed. Clinical data, compliance with treatment and clinical follow-up, and recurrence rates were examined. Statistical analysis performed include the Fisher exact test, Kaplan-Meier survival analysis, and log-rank test. ResultsFull compliance (defined as completion of the entire course of radiation therapy and clinical follow-up) with the BCT program was observed in only 36% of patients. Fifteen of the 35 noncompliant patients did not complete radiation therapy. A significantly higher local failure rate was observed: 8 of these 15 patients (53%) have had local failure. In contrast, patients who were either in full compliance with the BCT program or were deficient only in that they missed part of their clinical follow-up had local failure rates of 5% (1/20) and 10% (2/20), respectively. Age, race, stage of cancer, economic status (measured by availability of medical insurance), distance of patient's residence from the hospital, and education level were evaluated as potential predictors of compliance. None predicted patient compliance, although a trend toward higher compliance was noted in patients with a higher education level, as determined by literacy testing. ConclusionsCompliance with the BCT protocol at the authors' institution was worse than reported in clinical trials, and noncompliance translated into a significant increase in the local failure rate. Factors examined suggest that literacy may play a role in predicting compliance. Although BCT should be discussed with all breast cancer patients, the judicious application of clinical trial data to an institution's local population is warranted.
To determine if the mammalian target of rapamycin (mTOR) inhibitor CCI-779 can sensitize head and neck squamous cell carcinoma (HNSCC) to radiotherapy (XRT) and compare the radiosensitizing effects to cisplatin with its known considerable toxicity. Radiosensitizing effects of CCI-779 were assayed on HNSCC cell lines in vitro. CCI-779 (5 mg/kg), cisplatin (1 mg/kg), and XRT (2 Gy) alone and in combination were evaluated for antitumor activity in mice bearing FaDu and SCC40 xenografts. Effects of CCI-779 on radiation-induced activation of the Akt/mTOR pathway were analyzed. Although CCI-779 did not sensitize HNSCC cells to ionizing radiation in vitro, combination of CCI-779 and XRT significantly augmented the in vivo tumor growth-inhibitory effects of XRT and CCI-779 (P < 0.05). In addition, CCI-779 + XRT suppressed tumor growth more effectively than cisplatin + XRT (P < 0.05). CCI-779 + XRT significantly improved survival compared with XRT alone in both cisplatin-sensitive FaDu (P < 0.01) and cisplatin-resistant SCC40 (P < 0.05) xenograft mice. There were no additional benefits of adding cisplatin to CCI-779 + XRT. CCI-779 significantly attenuated irradiation-induced up-regulation of the mTOR pathway, increased apoptosis and displayed potent antiangiogenic activity in FaDu xenografts that was further enhanced by its combination with XRT (P < 0.05), which may explain the mechanism of its selective radiosensitizing effects in vivo and not in vitro. Antitumor activity of XRT was enhanced when combined with CCI-779 in HNSCC xenograft model. CCI-779 + XRT showed antitumor activity superior to conventional chemoradiotherapy with cisplatin. These results pave the way for clinical trials using molecular targeted therapy with CCI-779 in combination with XRT for HNSCC treatment.
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