Breast cancer is the most common malignant tumor in women in Panama. A little more than a thousand new cases are registered annually in our country. The vast majority of patients are women over 50 years of age, although I have noticed an increase in the number of patients under 50 years of age.
After the initial shock of the diagnosis, one of the questions I am most frequently asked by patients is what could have caused their cancer. In all honesty, my answer is that most of the time we do not have an exact cause, since cancer is a highly complex disease. Environmental, personal and even family factors influence its appearance. Being a condition that affects genes, its appearance at a given time is influenced by multiple factors: reproductive (early age of first menstruation, late menopause, number of previous pregnancies, not having breastfed, hormone replacement therapy, etc.), environmental factors (obesity, sedentary lifestyle, alcohol use, high-fat diets) and family factors (family history of breast cancer or other neoplasms such as ovarian, prostate, pancreatic cancer, etc.). When we come to describe these elements, I always clarify that having one or more risk factors, from a statistical perspective, is only a greater probability of developing a condition such as breast cancer, just as not having these characteristics is not a guarantee of that the disease cannot develop.
From the point of view of family history, it is necessary for patients to know that about 80% of people with breast cancer have what we know as sporadic cancer. These patients have no history of breast cancer or other cancer in the family. At some point in your life, biological and environmental factors induced changes in your breast cells that ultimately caused cancer to develop, but without an inheritance pattern, which is why we call it sporadic. The remaining 20% have a history of cancer in their close family (grandparents, parents, brothers, uncles, first cousins). We subsequently divided this 20% into 15% who are patients with a history of cancer in their family, but without a clear inheritance pattern in the affected relatives, who may not be close in nature. They have no identifiable genes associated with a mutation and are therefore not inherited. The remaining 5% corresponds to hereditary cancers. In these cases, a mutation has occurred, which can be transmitted to other family members, who have a high probability of passing the mutation and the susceptibility of suffering from cancer to the rest of their successive generations. We know these mutations as germline mutations. The genes most frequently affected by these mutations are BRCA1, BRCA2, TP53, PALB2, PTEN, CHECK2, RAD51, among others.
What clinical characteristics make one suspect hereditary breast cancer?
In addition to the history of a first- or second-degree relative with breast, ovarian or prostate cancer, the history of breast cancer in men and the age at which the cancer appeared in both the patient and their affected relative is very relevant. As we said at the beginning, the majority of patients with breast cancer present it after the age of 50; However, if breast cancer appears at an early age, before age 50 and particularly before age 40, it is one of the characteristics that alerts us to this condition. Likewise, if the cancer affects both breasts or is of the triple negative type (negative for estrogen receptors, progesterone and the Her2neu protein).
Why is it important to know if we have hereditary breast cancer?
The clearest and simplest answer is that every patient with suspected hereditary cancer should undergo a process that we call genetic counseling, in which geneticists and oncologists with training in hereditary cancer provide information about:
- Your chance of developing cancer or another second neoplasm.
- The probability of passing the mutated gene to your offspring.
- Early detection strategies and procedures to reduce the risk of other cancers.
- Therapeutic alternatives for hereditary tumors with drugs that have demonstrated effectiveness in these tumors (examples: PARP inhibitors).
How is hereditary cancer confirmed?
The first thing is the suspicion due to the clinical characteristics that we have previously mentioned. However, the diagnosis is established by a blood test that demonstrates the presence of the mutated gene in the germline.
No patient should have this test without first having undergone genetic counseling. It is an ethical duty of each doctor and the laboratories that perform it to ensure that the patient has attended genetic counseling, has signed the informed consent and understands the implication of the test and the biological and psychological impact that the result may derive. this, as well as the subsequent follow-up of the patient and his family.
Is genetic counseling done in Panama?
Yes, both in the private and public spheres. At the Insurance Fund's Genomics Institute, patients are evaluated, tests are performed and they work hand in hand with the National Oncology Institute, which has oncologists with training in hereditary cancer.
