Cancer and its treatment:

Cancer and its treatment: 

Cancer is defined as the uncontrolled growth of abnormal cells, which has the potential to invade nearby cells. Cancer is a genetic defect caused by DNA mutations that are acquired spontaneously or induced by environmental insults. These genetic alterations are heritable and being passed to daughter cells upon cell divisions.

There are six hallmarks of cancer:

1-self-sufficiency in growth signals,

2-insensitivity to growth-inhibitory signals,

3-evasion of cell death,

4- limitless replicative capacity,

5-development of sustained angiogenesis,

 6-ability to invade and metastasize.

 Cancer could be benign or malignant. Benign cancers (not so harmful) have fewer mutations, are well-differentiated, grow slowly and mitosis occur rarely and they are surrounded by capsule so they do not have the potential to invade. Benign tumors are fibroma, lipoma, chondroma, hemangioma, lymphangioma, leiomyoma, adenoma, and papilloma. Whereas malignant ones have a wide array of mutations, undifferentiated, mitosis are numerous, grow rapidly and they do not have the capsule so metastasis occurs to distant sites. Metastasis is secondary implants of the tumor that are discontinuous from the primary tumor. Malignant tumors are fibrosarcoma, liposarcoma, chondrosarcoma,  lymphomas, leiomyosarcomas, adenocarcinomas, and seminomas. As of 2019,18 million new cases of cancer occur in the world annually.

 It caused about 8.8 million deaths (15.7%).  In Pakistan, there are 148,000 newly diagnosed cases of cancer per year. Although the overall incidence rate of cancer in the developing world are half than those seen in the developed world in both genders, and cancer mortality rates are generally the same. Survival from cancer tends to be poorer in developing countries because of a combination of a late-stage ate diagnosis and limited access to timely and standard treatment options. And 101,000 deaths due to cancer per year.1 out of every 5 men and 1 out of every 6 women have cancer. The most common types of cancers in men are lung cancer, prostate cancer, colorectal, and stomach. As lung cancer is the leading cancer site in males, it comprises 17% of new cases of cancer and 23% of total cancer deaths. In women, common types of cancers are breast cancer, colorectal, lung, and cervical cancer. Breast cancer accounts for 23% of total cancer cases and 14% of cancer deaths. In children, acute lymphoblastic leukemia and brain tumor are most common. The factors that cause cancers are genetic defects, environmental factors, chemicals, and radioactive materials, smoking tobacco, alcohol, obesity, old age, and some viruses hepatitis B, hepatitis C (causes 70-85% of hepatocellular carcinoma) , human papillomavirus, human immunodeficiency virus, helicobacter pylori(causes gastric adenocarcinoma and MALT lymphoma), Epstein-Barr virus( Burkitt lymphoma, Hodgkin lymphoma, nasopharyngeal carcinoma, gastric carcinomas, and sarcomas).

Signs and symptoms of lung cancers are chronic cough from 2-3 months, hemoptysis, chest infection, weight loss, breathlessness, wheeze, lethargy, and weakness. In prostate cancer, there is polyuria, nocturia, incomplete emptying of the bladder, poor streaming, urgency, hesitancy, blood in urine/ semen. In colorectal cancer there is a change in bowel habits like diarrhea constipation, narrowing of stools, blood in stools or rectal bleeding, abdominal pain, weight loss are the common symptoms. In breast cancer, there is a lump/ swelling in the breast, redness, thickening of the skin, discharge from the nipple, and inversion of the nipple. In cervical cancer, signs and symptoms are blood spots or light bleeding between or following the periods, heavy menstrual bleeding, postcoital bleeding, dyspareunia, postmenopausal bleeding, persistent pelvic or back pain. Acute lymphoblastic leukemia causes lethargy, pale skin, breathlessness, repeated infections, frequent bleeding from the gums, epistaxis, high temperature, night sweats, bone, and joint pains , and easily bruised skin. In brain tumors patient complaints of persistent headache, vomiting, seizure, memory loss, fatigue, drowsiness, and sleep problems.

Most of the cancers can be prevented by avoiding smoking, not drinking alcohol, maintaining healthy weight, eating fruits, whole grains, vegetables, avoiding exposure to chemicals and radioactive materials and by the vaccination of the hep B, C and other infectious viruses. Early detection be done by screening methods, which will help in the treatment of cancer in the early stages.

Imaging modalities available for the diagnosis of cancer are: computerized tomography (CT) scan, bone scan, magnetic resonance imaging (MRI), positron emission tomography (PET) scan, ultrasound, x-ray, mammography. Laboratory test: complete blood examination, urine test, tumor markers, viral markers also help in the diagnosis of cancer. Biopsy, by collecting the sample of cells for testing in the laboratory. In most cases, it is the definitive way to diagnose cancer.

Treatment :

1-surgery: the purpose of surgery is to remove cancer as much as possible or to remove the whole organ.

2- Chemotherapy: many drugs that use powerful chemicals to kill fast-growing cancerous cells or stop them from dividing.

3- Radiation therapy: in it, high powered energy beams such as x-rays, are used to kill the cancer kills. Radiations can be given from the machine present outside your body called external beam radiation, or it can be placed within the body of the patient called brachytherapy

4- Bone marrow transplant is also known as a stem cell transplant, which is present within the bones and makes blood cells. A bone marrow transplant can be taken from the patient himself or from the donor.

5- Immunotherapy, also known as biological therapy, in which the body’s own immune system is used to fight cancer. It can be done in a couple of ways: by stimulating or boosting the natural defenses of your immune system so it works harder to find and attack the cancerous cells, or by making the substances in the laboratory that are like the components of the immune system and using them to help to restore or improve the immune system so it could fight with cancer cells.

6- Hormone therapy: some cancers are fueled by the hormones of our own body, so by removing those hormones or blocking their effect, we can stop the growth of cancer cells. Some types of breast cancers are affected by hormones like estrogen and progesterone, so the drug Tamoxifen which blocks the estrogen receptor is used in its treatment.

7-Targeted drug therapy: it focuses on the specific abnormalities within the cancer cells that allow them to survive.