Preoperative neoadjuvant therapy, broadly speaking, is the adjuvant therapy that patients with gastric cancer receive before surgery. In a narrow sense, it is divided into two parts: one is treatment for gastric cancer that is evaluated to have a chance of radical surgery, with the aim of shrinking the lesion and improving the surgical resection and cure rate; the other is preoperative conversion therapy, which converts unresectable tumors into resectable ones with the aim of radical resection.
Neoadjuvant therapy
The objectives of neoadjuvant therapy are as follows: to reduce the size of the lesion, to improve the surgical resection rate and cure rate, to reduce the risk of surgery and the patient’s tumor burden; to control to some extent the preoperative presence of microscopic cancer or microscopic metastases, which helps to reduce the risk of metastasis or recurrence with the aim of improving survival; to verify the efficacy of the chemotherapy regimen used and to provide a reference for the postoperative selection of treatment options.
For those with no distant metastases or only isolated sites of metastases that are not particularly deeply infiltrated and where the lymph node metastases around the stomach are still within surgical control, physicians usually consider preoperative neoadjuvant chemotherapy. Specifically, locally advanced gastric cancer can usually be considered for neoadjuvant therapy if it is clinically resectable without distant metastases, if the clinical staging is consistent with stage cIII and above, or if metastases are present but are confined to one organ and there are less than 3 metastatic lesions.
The usual preoperative neoadjuvant therapy is chemotherapy. Several studies have demonstrated that neoadjuvant chemotherapy + surgery + adjuvant chemotherapy significantly improves radical resection rates and overall survival after radical resection compared with surgery alone ± adjuvant chemotherapy, with more significant quality-of-life benefits and better patient tolerance. The classic MAGIC study demonstrated higher 5-year survival rates with chemotherapy before and after surgery compared with surgery alone (36% and 23%, respectively), but similar postoperative complication rates (46% and 45%, respectively). 24%), and similar rates of postoperative complications.
Translational therapy
In patients with unresectable tumors, such as those with deep infiltration, indistinguishable from surrounding tissues and organs, or involving important blood vessels and nerves, and with severe distant metastases, physicians may consider conversion therapy with the goal of converting the tumor to resectable so that radical resection is possible.
These patients usually have very advanced disease, have a large tumor load, and are often in poor physical condition, so physicians are cautious in their choice of translational therapy options and treatments. The most common translational therapy is chemotherapy, sometimes supplemented by radiotherapy and targeted therapy. It has been shown that translational therapy can help improve quality of life, but the effectiveness of translational therapy on tumor control, factors influencing efficacy, and ideal regimens are still being explored.
Of course, not all patients will benefit from neoadjuvant therapy, and there are still some unanswered questions about neoadjuvant therapy. The decision to proceed with neoadjuvant therapy will depend on the tumor condition, the patient’s physical condition, and other factors, as well as the choice of the appropriate treatment plan. (Contributed by Xin Wang, Department of Gastrointestinal Oncology, The First Affiliated Hospital of China Medical University)