Major Trials

The studies listed below represent the first major clinical trials to evaluate risk reduction for people at high risk of breast, prostate, lung, colorectal, ovarian, cervical, and lung cancer. Analysis of the data gathered from these large trials continues to contribute valuable understanding about related issues, including screening, patient-reported symptoms, quality of life, nutrient impact, population/ethnicity differences, study design and implementation, and many others. 

Breast Cancer Prevention Trial (BCPT) [1992 - 1998]

The Breast Cancer Prevention Trial (BCPT) was designed to see whether taking the drug tamoxifen (Nolvadex®) could prevent breast cancer in women who are at an increased risk of developing the disease. The BCPT was also looking at whether taking tamoxifen decreases the number of heart attacks and reduces the number of bone fractures in these women.

The final results of the BCPT showed a 45 percent reduction in breast cancer incidence among participants taking tamoxifen were about half of those for women taking a placebo.  The risks of stroke, deep-vein thrombosis, and cataracts — possible side-effects of tamoxifen treatment — were also increased, mainly in post-menopausal women.

Summary of Protocol

Randomized, Placebo-Controlled Clinical Trial to Determine the Worth of Tamoxifen for Preventing Breast Cancer

Run by

National Surgical Adjuvant Breast and Bowel Project (NSABP ) under grants from NCI

Publications

List of publications about BCPT

Prostate Cancer Prevention Trial (PCPT) [1993 - 1998]

The main study objective was to see whether the drug finasteride (Proscar™) can prevent prostate cancer in men age 55 and older. Additional objectives were to: determine if finasteride affects the stage and grade of prostate cancers; see if finasteride affects the number of deaths from prostate cancer and the number of deaths from all cancers; see if finasteride changes the occurrence and type of noncancerous prostate growth; estimate the accuracy of digital rectal exam and PSA testing separately and together in detecting whether a man has prostate cancer; and measure how long-term treatment with finasteride affects a man's urinary and sexual function.

Summary of Protocol

Phase III Randomized, Double-Blind, Placebo-Controlled Study of Finasteride (Proscar) for the Chemoprevention of Prostate Cancer

Run by

SWOG

NCI Materials

Publications

List of publications about PCPT

PLCO Cancer Screening Trial [1993-2001; 2009-2012]

The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) is a large population-based randomized trial designed and sponsored by NCI to determine the effects of screening on cancer-related mortality and secondary endpoints in men and women aged 55 to 74. The screening component of the trial was completed in 2006. Participants are being followed and additional data will be collected through 2015. In 2011, the follow up was streamlined and began being moved from the Screening Centers to the Centralized Data Coordinating Center (CDCC). Numerous epidemiologic and ancillary studies are also underway to answer related crucial questions.

PLCO Background

Run by

NCI Division of Cancer Prevention

Publications

List of publications about PLCO

ASCUS / LSIL Triage Study for Cervical Cancer [1996-2001]

The ASCUS/LSIL Triage Study for Cervical Cancer (ALTS) is a clinical trial to find the best way to help women and their doctors decide what to do about the mildly abnormal and very common Pap test results known as ASCUS and LSIL. About three million women in the United States are diagnosed with ASCUS and LSIL each year. Organized and funded by the National Cancer Institute, ALTS included more than 5,000 women. It began in November 1996 and concluded at the end of 2000 showing that the role of HPV testing in identifying women at high risk for cervical cancer.

Run by

NCI Division of Cancer Prevention

NCI Materials

DCP ASCUS/LSIL Page

Publications

List of publications about ASCUS/LSIL Triage Study

Study of Tamoxifen and Raloxifene (STAR) [1999 - 2006]

The Study of Tamoxifen and Raloxifene (STAR) was a clinical trial designed see how the drug raloxifene compares with the drug tamoxifen in reducing the incidence of breast cancer in postmenopausal women who are at increased risk of the disease. Initial results showed that raloxifene is as effective as tamoxifen in reducing the breast cancer risk of the women on the trial. In STAR, both drugs reduced the risk of developing invasive breast cancer by about 50 percent. In addition, within the study, women who were assigned to take raloxifene daily and who were followed for an average of about 4 years, had 36 percent fewer uterine cancers and 29 percent fewer blood clots than the women who were assigned to take tamoxifen. Uterine cancers, especially endometrial cancers, are a rare but serious side effect of tamoxifen. Both tamoxifen and raloxifene are known to increase a woman's risk of blood clots.

Summary of Protocol

Study of Tamoxifen and Raloxifene (STAR) for the Prevention of Breast Cancer in Postmenopausal Women

Run by

National Surgical Adjuvant Breast and Bowel Project (NSABP )

NCI Materials

Publications

List of publications about STAR

Selenium and Vitamin E Cancer Prevention Trial (SELECT) [2001 - 2008]

The largest-ever prostate cancer prevention trial with 35,534 participants, the Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a randomized phase III trial to determine the effectiveness of selenium and vitamin E, either alone or together, in preventing prostate cancer. It was coordinated by SWOG (formerly the Southwest Oncology Group), a network of about 4,000 researchers, at over 400 SELECT sites throughout the United States, Puerto Rico, and Canada.

Summary of Protocol

Phase III Randomized Study of Selenium and Vitamin E for the Prevention of Prostate Cancer (SELECT Trial)

Run by

SWOG

NCI Materials

Publications

List of publications about SELECT

National Lung Screening Trial (NLST) [2002-2010]

The National Lung Screening Trial (NLST) compared two ways of detecting lung cancer: low-dose helical computed tomography (CT) and standard chest X-ray. Both chest X-rays and low-dose helical CT scans have been used to find lung cancer early, but the effects of these screening techniques on lung cancer mortality rates had not been determined. Findings showed that participants who received low-dose helical CT scans had a 20.0 percent lower risk of dying from lung cancer than participants who received standard chest X-rays.

Summary of Protocol

National Lung Screening Trial (NLST)

Run by

NCI and the American College of Radiology Imaging Network

NCI Materials

NLST Page

Publications

List of publications about NLST