Salivary gland cancers: current treatments, molecular characteristics and new therapies

Salivary gland cancers are relatively rare and quite diverse. Current therapy relies on local ablation. There are few large clinical trials or randomized trials to guide treatment, especially for metastatic disease. This article reviews the epidemiology, staging, molecular characteristics, and treatment evidence for the most common types of salivary cancers and suggests potential future diagnostic and treatment directions. Progress in understanding the molecular and cell biology of salivary gland cancers may lead to the development of targeted therapies in these rare tumors. Multidisciplinary and multi-institutional collaborative studies are needed to help improve survival in salivary gland cancers.

Phase II Study of Lapatinib in Recurrent or Metastatic Epidermal Growth Factor Receptor and/or erbB2 Expressing Adenoid Cystic Carcinoma and Non–Adenoid Cystic Carcinoma Malignant Tumors of the Salivary Glands

Purpose

Expression of erbB2 and/or epidermal growth factor receptor (EGFR) is associated with biologic aggressiveness and poor prognosis in malignant salivary gland tumors (MSGTs). This phase II study was conducted to determine the antitumor activity of lapatinib, a dual inhibitor of EGFR and erbB2 tyrosine kinase activity, in MSGTs.

Patients and Methods

Patients with progressive, recurrent, or metastatic adenoid cystic carcinoma (ACC) immunohistochemically expressing at least 1+ EGFR and/or 2+ erbB2 were treated with lapatinib 1,500 mg daily, in a two-stage cohort. Patients with non-ACC MSGTs were treated as a separate single-stage cohort.

Results

Of 62 patients screened, 29 of 33 (88%) ACC and 28 of 29 (97%) non-ACC patients expressed EGFR and/or erbB2. Forty patients with progressive disease were enrolled onto the study. Among 19 assessable ACC patients, there were no objective responses, 15 patients (79%) had stable disease (SD), nine patients (47%) had SD ≥ 6 months, and four patients (21%) had progressive disease (PD). For 17 assessable non-ACC patients, there were no objective responses, eight patients (47%) had SD, four patients (24%) had SD ≥ 6 months, and nine patients (53%) had PD. The most frequent adverse events were grade 1 to 2 diarrhea, fatigue, and rash. Eight paired tumor biopsies for correlative studies were procured; results did not correlate with clinical outcome.

Conclusion

Although no responses were observed, lapatinib was well tolerated, with prolonged tumor stabilization of ≥ 6 months in 36% (95% CI, 21% to 54%) of assessable patients. The antitumor effects of lapatinib in MGSTs appear mainly cytostatic, hence evaluation of other molecular targeted agents, or combinations with lapatinib, may be considered. Continued efforts should be made to gain better understanding into the biology of this heterogeneous group of malignancies.

Clinical Cancer Advances 2005: major research advances in cancer treatment, prevention, and screening--a report from the American Society of Clinical Oncology

This year, for the first time, the American Society of Clinical Oncology (ASCO) is publishing Clinical Cancer Advances 2005: Major Research Advances in Cancer Treatment, Prevention, and Screening, an annual review of the most significant clinical research presented or published over the past year across all cancer types. ASCO embarked on this project to provide the public, patients, policymakers, and physicians with an accessible summary of the year's most important research advances. While not intended to serve as a comprehensive review, this report provides a year-end snapshot of research that will have the greatest impact on patient care. As you will read, there is much good news from the front lines of cancer research. These pages report on new chemotherapy regimens that sharply reduce the risk of recurrence for very common cancers; the "coming of age" of targeted cancer therapies; promising studies of drugs to prevent cancer; and improvements in quality of life for people living with the disease, among many other advances. Survival rates for cancer are on the rise, increasing from 50% to 64% over the last 30 years. Cancer still exacts an enormous toll, however. Nearly 1.4 million Americans will be diagnosed this year, and some 570,000 will die of the disease. Clearly, more research is needed to find effective therapies for the most stubborn cancer types and stages. We need to know more about the long-term effects of newer, more targeted cancer therapies, some of which need to be taken over long periods of time. And we need to devote far greater attention to tracking and improving the care of the nearly 10 million cancer survivors in the United States today. Despite these and other challenges, the message of this report is one of hope. Through the dedicated, persistent pursuit of clinical research and participation in clinical trials by people with cancer, we steadily uncover new and better ways of treating, diagnosing, and preventing a disease that touches the lives of so many. I want to thank the Editorial Board members, the Specialty Editors, and the ASCO Cancer Communications Committee for their dedicated work to develop this report, and I hope you find it useful.