Neoadjuvant Vs. Adjuvant Therapy In GI Cancers: Current Evidence And Best Practices

Cancer is a complicated disease, but the ultimate goal of any doctor treating a patient with cancer is straightforward. That is, use every available therapy to achieve the best possible outcome. These two types of therapies in gastrointestinal (GI) cancers are incorporated frequently into many of the care regimes. Even though the both therapies can impact significantly a course of treatment plans, they do differ in some areas such as timing, intent, and value. These all exceptional cases are depending on the type of cancer, stage, and patient-specific factors.

This blog will provide an overview of neoadjuvant vs adjuvant therapy in GI cancers, describe how they relate to GI cancers, summarize the existing evidence for their use, and highlight current best practices that are influencing patient outcomes.

What is Neoadjuvant Treatment?

Neoadjuvant treatment is treatment that is done prior to surgery to shrink tumors and improve surgery results. In gastrointestinal cancers, neoadjuvant therapy is typically chemotherapy, radiation or both.

Esophageal cancer: Increases survival rate with chemoradiotherapy.
Rectal cancer: Decreases recurrence and allows some patients the option of avoiding permanent colostomy.
Pancreatic cancer: Used to treat patients with borderline resectable tumors to improve surgical resectability.

What is an Adjuvant Treatment?

Adjuvant treatment is treatment that happens post-surgery that takes place to remove residual cancer cells and decrease chance of recurrence. Commonly chemotherapy, radiation, or targeted therapy based on tumor location.

Colon cancer: Beneficial for Stage III patients postoperatively.
Gastric cancer: Chemoradiation is standard for adjuvant treatment after surgery.
Pancreatic cancer: Adjuvant chemotherapy longer survival post-operatively.

Understanding Neoadjuvant vs. Adjuvant Therapy in GI Cancers

In gastrointestinal (GI) cancers, the decision to deliver therapy before or after surgery matters in terms of outcomes. Both neoadjuvant vs. adjuvant therapies in GI cancers are defined clearly and are dependent on tumor type, tumor site, tumor stage, and the overall health of the patient. Neoadjuvant therapy is delivered prior to surgery to decrease the tumor burden and to allow for easier and potentially more successful resection. Adjuvant therapy is delivered after the surgery to eradicate residual cells and reduce recurrence risk.

The decision between the adoption of neoadjuvant vs. adjuvant therapy in GI cancers is based on a variety of factors, particularly the resectability of the tumor, recurrence risk, and the GI cancer type.

Aspect	Neoadjuvant Therapy	Adjuvant Therapy
Timing	Before surgery	After surgery
Purpose	Shrink tumor, increase resectability	Eliminate residual cancer cells, prevent recurrence
Common modalities	Chemotherapy, radiation, or both	Chemotherapy, radiation, targeted therapy
Used in	Esophageal, rectal, pancreatic (borderline resectable)	Colon, gastric, pancreatic (post-surgery)
Benefits	Tumor downstaging, better surgical outcomes, organ preservation	Improves survival, reduces recurrence
Considerations	May delay surgery, not suitable for all patients	Depends on surgical margins, lymph node involvement

Current Evidence and Recommended Best Practices in GI Cancer Therapies

The medical field has progressed significantly with the addition of clinical evidence regarding the use of neoadjuvant vs. adjuvant treatments in GI cancers. Neoadjuvant and adjuvant therapies for GI cancers are now more personalized and focused on improving surgical results, decreasing recurrence and improving overall survival. Updated guidelines and continued research will continue to inform the best use of neoadjuvant and adjuvant therapies across different GI cancers.

Best Practices of Neoadjuvant vs. Adjuvant Therapy in GI Cancers

These are some current best practices of oncologists and multidisciplinary care teams:

Perform molecular profiling before starting the treatment to optimize therapy plans.
Utilize neoadjuvant chemoradiotherapy for esophageal and rectal cancer in order to downstage tumors and improve margins for surgical resection.
Analyze the resectability of pancreatic cancer in borderline cases to be able to provide neoadjuvant therapy when appropriate.
Initiate adjuvant therapy within 6-8 weeks of surgery in order to maximize effectiveness.
Utilize evidence-based guidelines such as NCCN or ESMO to choose appropriate therapy regimens.
Assess patient response via imaging and biomarkers to determine efficacy while a patient is undergoing neoadjuvant treatment.
Review patient-specific variables during therapy selection including performance status, comorbidities, and lifestyle factors.
Utilize multidisciplinary tumor boards to determine timing and sequence of each therapeutic intervention.

The Practical Impact of Neoadjuvant vs. Adjuvant Therapy in GI Cancers

Choosing between neoadjuvant or adjuvant treatment can impact their responsiveness in gastrointestinal cancers. The two may offer different advantages based on several variables related to their tumor type, stage, and patient characteristics. A better understanding of their indications can provide additional treatment benefits and improve patient quality of life.

Tumor Downstaging and Surgical Impact

Neoadjuvant therapy reduces pre-treatment tumor size, so that surgical excision can be performed more completely and with less invasive surgical approaches. Because this is important in cancers involving organ preservation (esophageal and rectal cancers), it can improve postoperative function.

Eliminating Residual Disease

Adjuvant therapy aims at destroying microscopic disease that may remain after surgical excision, reducing the probability of cancer recurrence. Adjunct chemotherapy is extremely powerful in particular for colon and gastric cancers, where adjunct therapy improves survival after fundamental treatment.

Timing and Coordination of Care

Initiating adjuvant therapy within 6 to 8 weeks of surgery is essential to maximize adjuvant therapy impact. Continued evaluation through imaging and biomarkers while on neoadjuvant therapy are essential to make treatment decisions and surgical planning, thus providing continuum of care.

Individualized Multidisciplinary Care

Individualized treatment decisions based on the collaborative input of oncologists, surgeons, radiologists, and pathologists, will determine the best therapy sequence for each patient. Collaborative care will lead to improved prognosis and overall patient care.

Moving Toward More Personalized GI Cancer Treatment

The treatment of gastrointestinal cancers with neoadjuvant vs. adjuvant therapy in GI cancers is no longer a one-size-fits-all proposition. High-level diagnostic tools, clinical knowledge and evidence, as well as the development of multi-disciplinary care and treatment pathways are now allowing treatments to be tailored to the baseline characteristic of patients and tumors to optimize treatment for each individual and each situation.

Speak to your oncologist today about which treatment strategy presents an optimal approach to your condition, neoadjuvant, adjuvant, or both. Personalized, timely intervention can make all the difference in your cancer care journey.