Lung cancer is the leading cause of cancer deaths worldwide. People who smoke have the greatest risk of lung cancer, though lung cancer can also occur in people who have never smoked. The risk of lung cancer increases with the length of time and number of cigarettes you’ve smoked. If you quit smoking, even after smoking for many years, you can significantly reduce your chances of developing lung cancer. Types of Lung Cancer The two general types of lung cancer include: -Small cell lung cancer. Small cell lung cancer occurs almost exclusively in heavy smokers and is less common than non-small cell lung cancer. -Non-small cell lung cancer. Non-small cell lung cancer is an umbrella term for several types of lung cancers. Non-small celllung cancers include squamous cell carcinoma, adenocarcinomaand large cell carcinoma.

Esophagal cancer is cancer that occurs in the oesophagus- a long, hollow tube that runs from your throat to your stomach. Your oesophagus helps move the food you swallow from the back of your throat to your stomach to be digested. Esophageal cancer is the sixth most common cause of cancer deaths worldwide. The two most common forms of esophageal cancer are: -Squamous cell carcinoma: Cancer that forms in the thin,flat cells lining the inside of the esophagus. This cancer is ost often found in the upper and middle part of the esophagus, but can occur anywhere along the esophagus. This is also called epidermoid carcinoma. -Adenocarcinoma: Cancer that begins in glandular cells.Glandular cells in the lininng of the esophagus produce and release fluids such as mucus. Adenocarcinomas usually form in the lower part of the esophagus, near the stomach.

Cancer that begins in the colon is called colon cancer, while cancer in the rectum is known as rectal cancer. Cancers that affect either of these organs may be called colorectal cancer. How does Colorectal Cancer develop? Most colorectal cancers begin as small precancerous (adenomatous or serrated) polyps. These polyps usually grow slowly and do not cause symptoms until they become large or cancerous. This allows the opportunity for detection and removal at this pre-cancerous polyp stage before the development of cancer.

Most ovarian cancers start in the ovary’s epithelium, or outer lining. In the early stages, there may be few or no symptoms. If symptoms do occur, they can resemble those of other conditions, such as premenstrual syndrome, irritable bowel syndrome, or a temporary bladder problem. However, in ovarian cancer, the symptoms will persist and worsen. Types of Ovarian Cancer Types of ovarian cancer based on the type of cell in which they form. There are three common cell types: Epithelial cells: which occur in the lining of the surface of the ovary. Epithelial tumors are the most common and the most invasive. They occur in around 85–90% of people with ovarian cancer. Germ cells: which will become eggs for reproduction. Germ cell tumors are often benign. In 90% of cases that become cancerous, treatment is effective Stromal cells: which release hormones and link up the structures of the ovaries

The stomach is a sac-like organ that helps mixing food and gastric juices and delivers to duodenum. Development of stomach cancer Stomach cancers tend to develop slowly over many years. Before a true cancer develops, pre-cancerous changes often occur in the inner lining (mucosa) of the stomach. These early changes rarely cause symptoms, so they often go undetected.