DISEASE CHARACTERISTICS:

• Meets criteria for 1 of the following:

  • Known hereditary non-polyposis colon cancer (HNPCC)-associated mutation of MLH1, MSH2, MSH3, MSH6, PMS1, or PMS2 identified by gene sequencing
  • Fulfills Amsterdam criteria with 1 or more HNPCC-associated cancers

• No known or suspected malignancy of the breast or endometrium

  • Must have had a screening mammogram within the past 12 months if age 40 or over

PATIENT CHARACTERISTICS:

Age:

• 25 to 50

Sex:

• Female

Menopausal status:

• No postmenopausal patients with amenorrhea for more than 1 year

Performance status:

• Not specified

Life expectancy:

• Not specified

Hematopoietic:

• Not specified

Hepatic:

• No liver dysfunction or disease (e.g., hepatic adenomas or carcinoma)
• Liver function tests normal

Renal:

• Not specified

Cardiovascular:

• No active thrombophlebitis
• No prior or concurrent thromboembolic disorders or cerebrovascular disease
• No concurrent hypertension that is not well controlled
• No coronary artery disease

Other:

• Not pregnant
• Negative pregnancy test
• Fertile patients must use effective barrier contraception during the first month of study therapy
• No undiagnosed vaginal bleeding
• No gallbladder disease
• No hypersensitivity to medroxyprogesterone contraceptive injection
• No concurrent uncontrolled depression
• No prior or concurrent epilepsy
• No prior or concurrent diabetes
• No tobacco smoking for patients age 35 to 50
• No alcohol dependence or illicit drug use
• No other significant medical history or psychiatric problems that would preclude study participation
• Fasting triglycerides no greater than 400 mg/dL
• Cholesterol no greater than 240 mg/dL
• Low-density lipoprotein (LDL) no greater than 160 mg/dL
• High-density lipoprotein (HDL) at least 35 mg/dL

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• At least 2 years since prior chemotherapy

Endocrine therapy:

• At least 4 months since prior oral contraceptives, medroxyprogesterone, or other hormonal exposure (e.g., hormonal intrauterine device, tamoxifen, raloxifene, or other selective estrogen receptor modulators)
• At least 4 months since prior systemic steroids (e.g., prednisone)
• No concurrent systemic steroids (e.g., prednisone)

Radiotherapy:

• No prior pelvic irradiation

Surgery:

• At least 3 months since prior endometrial biopsy, hysteroscopy, dilation and curettage, or placement of an intrauterine device
• No prior hysterectomy (patients may be scheduled for a prophylactic hysterectomy)
• No prior bilateral oophorectomy

Other:

• No other concurrent participation in a protocol with pharmacological intervention