South Korean actress Kang Seo-ha, known for her performances in K-dramas like First Love Again and The Flower in Prison passed away at the age of 31 after a long battle with stomach cancer. Her family also confirmed the news on Monday. Kang's family took to Instagram, and posted a video along with a long note in remembrance of her.“I still can’t believe it, unnie. Even while enduring such immense pain, you worried about those around you and about me. Even though you couldn’t eat for months, you insisted on paying for my meals with your own card and never let me skip a meal. My angel, who left us far too soon. Even as you endured everything with painkillers, you said you were grateful that it wasn’t worse, and I felt truly ashamed. My dear sister, you went through so much. I hope you are only happy and free from pain where you are now,” the note read.A memorial service is also being organized at Seoul St Mary's Hospital and the funeral procession is scheduled at 7.40am on July 16 (KST). View this post on Instagram A post shared by 은 (@feb.eun)]]> Kang Seo Ha's CancerIt was in 2024 that Kang was diagnosed with advanced stomach cancer. As per reports, she had stage IV stomach cancer and underwent treatment, including multiple rounds of chemotherapy, while she continued to fulfill her professional commitments. However, in mid-2025, her health rapidly declined, leading to her death. As per the National Cancer Institute, US, cancer stage describes the extent of cancer in the body, which includes the size of the tumor, whether it has spread, and how far has it spread from where it was first formed.In stage IV stomach cancer, which Kang too was suffering from, the cancer spreads to other body parts, mostly lungs, liver, distant lymph nodes, and the tissue that lines the abdomen wall. Stage IV stomach cancer, also known as metastatic stomach cancer, occurs when cancer cells spread from the stomach to other parts of the body through the lymphatic system or bloodstream. The new tumors are still made up of stomach cancer cells, not cells from the organs they’ve reached. So, if the cancer spreads to the lungs, it's still considered stomach cancer — not lung cancer — and is referred to as metastatic stomach cancer.Stomach Cancer And Its TypesThe National Cancer Institute, US, notes that stomach cancer starts in the cells lining the stomach. There are various types of stomach cancers including:Adenocarcinoma of the stomach, which begins in the mucus-producing cells in the innermost lining of the stomach. Nearly all stomach cancers are adenocarcinomas.Gastroesophageal junction adenocarcinoma (GEJ) is a cancer that forms in the area where the esophagus meets the gastric cardia. GEJ may be treated similarly to stomach cancer or esophageal cancer.Gastrointestinal neuroendocrine tumors are cancers that begin in neuroendocrine cells (a type of cell that is like a nerve cell and a hormone-making cell) that line the gastrointestinal tract.Gastrointestinal stromal tumors (GIST) begin in nerve cells that are found in the wall of the stomach and other digestive organs. GIST is a type of soft tissue sarcoma. Primary gastric lymphoma is a type of non-Hodgkin lymphoma that forms in the stomach. Most primary gastric lymphomas are either mucosa-associated lymphoid tissue (MALT) gastric lymphoma or diffuse large B-cell lymphoma of the stomach.