As discussed in a previous post, a biopsy is an essential component of cancer treatment. It proves the existence of cancer and helps plan treatment. Under certain circumstances, however, treatment can be instituted even without biopsy confirmation of cancer.
Some such situations are:
1. Deeply located tumors: Tumors located in certain locations, such as the pancreas, are difficult to biopsy due to technical limitations. This is especially true when the tumor is small in size and located very close to major blood vessels. When the suspicion of cancer is high (based on other parameters like clinical and radiologic findings), doctors often proceed to perform a definitive cancer operation without a biopsy. Cancer is only confirmed on the post-operative biopsy of the resected organ.
2. Risk of cancer spread with biopsy: As discussed in a previous post, in the vast majority of cases, biopsy does not cause the spread of cancer. But in early ovarian cancer, a pre-operative biopsy can potentially upstage the disease. Therefore, in suspected early ovarian cancer, the presence or absence of cancer is confirmed only during surgery, when the entire tumor is removed for pathological analysis.
3. When the biopsy will not alter treatment: In certain organs, for example, the kidney, a tumor is far more likely to be cancerous than not. (see this post to know the difference between a tumor and a cancer). In such situations, a negative biopsy result cannot definitively rule out the presence of a cancer. This means that the treatment will not change whether the biopsy confirms cancer or not – and hence a biopsy may not be recommended at all.
4. Oncological Emergencies: In urgent situations, there may be no time for biopsy confirmation of cancer. For example, a patient may present with complete intestinal obstruction due to a colonic tumor. Or massive bleeding from a growth in the stomach. Under these circumstances, based on clinical judgement, definitive treatment may be initiated without doing a pre-treatment biopsy.
5. Low morbid surgeries: In certain cases, such as small skin tumors, the definitive cancer surgery of a wide excision carries very little morbidity, and histopathological confirmation of cancer can as well be done after complete wide excision, rather than perform a biopsy followed by definitive resection.
To summarize, there are situations where definitive cancer surgery is performed pending biopsy proof of cancer. This is based on clinical judgement in individual cases. On rare occasions, the final histopathology result following such operations may show some disease other than cancer, but that is an acceptable clinical outcome.