The transformation of a normal cell into a cancer cell is a long process in the human body.
Cancer encompasses a large group of more than 100 diseases. Cancer cells can appear on any organ or tissue in the body and spread to other organs. More than 400,000 new cases of cancer are detected each year in France, making prevention and early detection real public health issues. “Any cancer at the beginning stage, when the first cells become autonomous, is absolutely undetectable” immediately reminds us of Dr Jérôme Viguier, oncologist at the National Cancer Institute. In addition, there is a factor that can make it difficult to detect cancers for a very long time. As the oncologist explains to us, between the moment of the pre-cancerous lesion and the cancer, several years, even ten years, often pass: “Depending on its location, depending on the organs around it and depending on how it develops, the tumor can be more or less telling.” For example :
► pancreatic cancer: “If it develops in the part called the “tail of the pancreas”, the tumor will grow for quite a long time before giving symptoms. On the other hand, if the cancer develops in the head of the pancreas (next to the digestive tract and bile ducts), it will quickly compress the organs, which can cause jaundice, pain, and digestive problems.
► prostate cancer: most often, it develops slowly and at an advanced age. “If the tumor is close to the urinary tract, it can give symptoms very quickly. Whereas if it develops further around the prostate, it can grow for a long time before giving symptoms.”
► breast cancer: “If it develops deep, at the junction with the chest wall, the symptoms will be rather late. But if this cancer develops just under the skin on the surface of the breast, this can quickly cause retraction of the skin , discharge from the nipple or the appearance of an easily palpable lump.”
► colorectal cancer: “A tumor that develops in the wall of the colon, rather outwards, may not block the digestive tract and therefore not cause significant symptoms.”
Rarer, cancers of unknown primary, which represent 3 to 5% of cancers, are also particularly difficult to detect. “These are cancers whose origin cannot be determined. They do not present characteristic signs allowing us to determine their area of birth” continues Dr. Viguier. They are often revealed by metastases, that is to say cancer cells which have spread in the body without the primary tumor being identified. To treat them best, we must try to identify their origin. In oncology, treatments are generally targeted according to the organ which is at the origin of the cancer cells. “This therefore requires carrying out examinations to propose the treatment which seems most suitable, unfortunately these cancers generally have a poor prognosis”, inform the specialist.
This is why screening programs are carried out in order to obtain a diagnosis before any symptoms and to benefit from better chances of cure, lighter treatments and fewer after-effects if cancer is detected. This is the case for breast cancer, cervical cancer and colorectal cancer for which there is organized screening. “So, on does a mammogram and a clinical examination to detect a breast tumor, a stool blood test to look for cancer starting in the colon or rectum or we look for the presence of abnormal cells or papillomavirus in the cervix before it progresses to symptomatic cervical cancer.”
Alongside screening, there are non-specific symptoms that can be warning signs: unexplained pain that lasts, significant and persistent digestive problems/digestive bleeding, unexplained weight loss outside of any diet, unusual chronic fatigue, loss of appetite, respiratory problems (unexplained persistent cough, chest pain, shortness of breath) or even persistent urinary problems. “All of these symptoms do not necessarily mean the presence of cancer. But you should be vigilant if they appear and are persistent, especially if they are unexplained, and consult a health professional.”