Methods

Recruitment of cases and controls

Eligible case patients are women (of any age) who meet the following criteria:

1. have a histologically confirmed (biopsy-positive) incident case of invasive primary breast cancer, diagnosed at the National Institute of Oncology’s Sheikha Fatma Centre in Rabat or the Cancer Research Institute of the Centre Hospitalier Universitaire (CHU) Hassan II in Fez;
2. are able to participate and provide biological specimens before the start of any treatment; and
3. provide signed informed consent.

Case patients are invited to participate at the time of referral for diagnostic biopsy, or failing that, as soon as possible after diagnosis. Reasons for declining to participate are recorded.

Eligible control subjects are women who reside in the same neighbourhoods as the case patients and are of a similar age (± 5 years), but who do not have and have not had breast cancer.

Potential case patients are identified and approached by the oncologist when they come to the hospital for their first consultation for breast cancer. Potential control subjects are identified and approached by the staff in health care centres located in the various districts of the city; hospital staff may also approach neighbours who accompany potential case patients to their consultation. Potential case patients and control subjects who meet the eligibility criteria and wish to participate in the study are asked to sign an informed consent form and agree to provide blood and urine samples.

Inclusion and exclusion criteria for cases

Case patients are women with breast cancer who visit the National Institute of Oncology in Rabat or the CHU Hassan II in Fez for a first consultation with an oncologist. The inclusion and exclusion criteria for cases are as follows:

Inclusion criteria:

1. incident invasive breast cancer diagnosed < 1 month before the consultation
2. patient provides signed informed consent to participate in the study
3. patient agrees to provide blood and urine samples

Exclusion criteria:

1. treatment of breast cancer (chemotherapy, radiotherapy, hormone therapy, or surgery) before the consultation
2. diagnosis of breast cancer ≥ 1 month before the consultation
3. pregnancy
4. history of cancer (except skin cancer) other than breast cancer
5. dialysis

Inclusion and exclusion criteria for controls

Controls and cases are matched on patient age and city district. Control subjects are selected from the populations residing in the same districts in health care centres, or are neighbours who accompanied case patients to the hospital for consultation. Control subjects are recruited according to the approved protocol and sign an informed consent form. The inclusion and exclusion criteria for controls are as follows:

Inclusion criteria:

1. no history of cancer (with the exception of skin cancer)
2. same patient age as the matched case (±5 years)
3. same place of residence as the matched case
4. subject provides signed informed consent to participate in the study
5. subject agrees to provide blood and urine samples

Exclusion criteria:

1. pregnancy
2. history of cancer (except skin cancer)
3. dialysis
4. subject is in the same family as the matched case patient