What Is the Difference Between Oncology and Surgery?

Ask a newly diagnosed patient what is troubling them and one question comes up early: oncology vs surgery, which one do I need? It is a fair question, but it is not a contest. Oncology is the whole subject of cancer care. Surgery is one of the things it uses. What separates them is reach: drugs go round in the blood and find cancer cells wherever they are hiding, while surgery works on one spot, the solid tumour and a little healthy tissue around it. The surgical oncologist sits where the two meet, and that is why oncology and surgical oncology get talked about together.

According to Dr. Sandeep Nayak, a surgical oncologist in Bangalore, nobody is really asked to pick between the two. Many solid tumours need both at some point. What changes from case to case is the sequence, and the cancer type, the stage and the patient’s fitness for surgery decide it.

Oncology is the field. Surgery is one tool inside it. At a cancer centre they sit side by side in one team of oncologists.

• Oncology: All of cancer care, from the first scan to the last follow-up visit. It has three main arms: medical, radiation and surgical.
• Medical oncology: The drug arm. Chemotherapy, targeted tablets, immunotherapy and hormone treatment go round in the blood, so they reach the main tumour, the lymph nodes and any organ it may have spread to, in one go.
• Surgery: The operating arm. The surgeon takes the tumour out from where it started, with a rim of normal tissue and the lymph nodes next to it.
• Radiation oncology: Beams of radiation aimed at one area. Local, like surgery, but with no incision.
• Why both exist: A drug can reach cells that scans can’t see, but it can’t take out a solid lump. Surgery gets the lump out, but a cell that has already moved on is beyond its reach.

A surgical oncologist is a surgeon who looks at cancer cases day in and day out. The job is bigger than the operation, and surgical oncology takes in the steps before and after it too.

• Biopsy: First, a piece of the tumour has to be taken out and looked at under a microscope. Quite often the surgeon does this, with a needle, an endoscope or a small cut.
• Staging: Once the scans and biopsy are in, the cancer gets a stage. The TNM system looks at three things: how big the tumour is, whether the nodes are involved, and whether it has spread. Every later decision leans on this.
• The operation: The surgeon wants a clear margin, which means healthy tissue all round the tumour, and the nearby lymph nodes out as well. Leaving cancer behind weakens the benefit of everything that follows.
• Function: Where it can be done, speech, swallowing and bowel or bladder function are kept safe, and what had to be removed is rebuilt.
• Relief of symptoms: Sometimes the cancer can’t be removed fully. An operation can still open a blocked bowel or stop a bleed, and the patient feels better for it.