Cancer

Cancer (a malignant tumor) is characterized by the presence of cancerous cells, so-called immortal cells with the ability to multiply indefinitely. The surrounding cells and the rest of the body cannot control the proliferation of cancerous cells, which are able to spread to other tissues and even to sites that are remote from the primary tumor (metastases).

Impact on public health:

Each year 10 million new cases of cancer are diagnosed worldwide. Cancer is responsible for 6 million deaths and is the second leading cause of death in industrialized countries (the first being cardiovascular diseases). The earlier a cancer is detected, the better the chances of treating it successfully.

Diagnosis: A diagnosis of cancer can only be confirmed by performing an anatomico-pathological examination on the tumor (a biopsy to identify modifications in tissues and cells).
· Clinical signs: Such signs depend on the type of cancer, where it is located, and how far developed it is. Signs vary greatly and may include coughing, abnormal bleeding, digestive disorders, continuous pain, swelling, weight loss, fatigue, etc.
· Additional tests: Medical imaging (x-ray, scan, Magnetic Resonance Imaging, ultrasound, endoscopy, etc.) may be used to determine the precise location and extent of the tumor (whether it has spread to neighboring tissues, metastases).

· Biological analyses: Tumor markers are substances secreted by cancerous cells. They can be detected in biological fluids—in particular, blood—with easy and accessible testing. The detection of tumor markers offers a more or less specific indication of the presence of a malignant tumor, and suggests to physicians which organ may be affected. For example, PSA (Prostate Specific Antigen) may be abnormally high both in the case of prostate cancer or an infection of the prostate. Measuring tumor markers gives physicians useful information to orient their diagnosis, but above all, it is by measuring changes in tumor marker levels that it is possible to monitor the patient's condition and assess whether treatment is effective.