Does presurgical treatment destroy important prognostic information

Excerpt

There are two common forms of presurgical treatment: a short course of treatment up to 2 weeks before surgery, and more prolonged periods of systemic therapy, commonly known as neoadjuvant therapy. Short courses of treatment have little effect on the major prognostic factors, with the possible exception of tumour grade. In particular, tumour size and node status do not change. In contrast, more prolonged courses of neoadjuvant therapy are used because they have a major influence on tumour size and, in some patients, node status. This review investigates the commonly used prognostic factors and how presurgical treatment might influence these factors. …