Preoperative neoadjuvant therapy is designed to bring the tumor down in stage, shrink the mass, and allow patients who would not otherwise be eligible for surgery to have a chance at radical resection while reducing the risk of recurrence. So, can surgery be done immediately after neoadjuvant therapy? The first time I saw a tumor, I had a chance to see it.
This article takes a look at the “start and finish” of neoadjuvant therapy and evaluating its efficacy.
How soon can I have surgery after neoadjuvant therapy?
After neoadjuvant therapy, how soon can I have surgery?
After neoadjuvant therapy is over, your doctor will consider two factors: how long the treatment will continue to work and how long the side effects of the treatment are likely to last. The timing of surgery is determined so that neoadjuvant therapy maintains control of the tumor and the side effects do not affect your tolerance for surgery.
Usually, surgery is scheduled within a window of 3 to 8 weeks after the end of neoadjuvant therapy.
During this interval, you will want to do three things:
1. Aggressively manage comorbidities, such as controlling blood pressure and blood glucose and adjusting lipids;
2. Increase nutritional support (tube feeding nutritional support is preferred) and be appropriately active;
3. Maintain a happy mood and meet the surgery in a good mental state.
How is the effect of neoadjuvant therapy assessed?
The easiest and most direct way to determine the effectiveness of neoadjuvant therapy for esophageal cancer is to look for any improvement in dysphagia symptoms. For example, if you were only able to eat a semi-liquid diet before treatment and can eat solid food after treatment, or if your existing symptoms such as dysphagia and chest and back pain are reduced, then neoadjuvant therapy is working.
In addition, some objective tests can help us determine the efficacy of neoadjuvant therapy:
1. Imaging tests such as chest CT and upper gastrointestinal imaging.
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After neoadjuvant therapy has been completed for a period of time, your doctor will evaluate your imaging to determine the size of the tumor and suspected metastatic lymph nodes before and after chemotherapy, and then determine the efficacy of neoadjuvant therapy by using the solid tumor treatment efficacy criteria. The most common clinical evaluation criteria are the World Health Organization (WHO) criteria and the RECIST (Response Evaluation Criteria in Solid Tumors) criteria.
In general, the “interval” between the end of treatment and the imaging evaluation is often about 2 weeks after neoadjuvant chemotherapy or 3 to 4 weeks after neoadjuvant radiotherapy.
So what are the metrics to look at to determine if neoadjuvant therapy is working? Let’s take RECIST, the new standard for evaluating the efficacy of solid tumors, as an example:
- Target lesion (i.e., primary site of esophageal cancer)
Complete response (CR): all target lesions are gone;
Partial remission (&p): all target lesions are gone;
partial remission ( partial response, PR): visible shrinkage of lesions compared to before treatment started;
progressive disease (PD): an increase in the number of lesions or a visible increase in the size of the lesions compared to the start of treatment;
Stable disease (SD): between PR and PD.
Stable disease (SD): between PR and PD.
- Non-target lesions (e.g., metastases, etc.)
Complete remission (CR): all non-target lesions are gone and tumor marker levels are back to normal;
Incomplete remission/stable (IR/SD): non-target lesions remain and tumor marker levels remain abnormal;
Progression of lesions (PD): new lesions appear or existing lesions increase in size and progress.
It is important to note that both the WHO criteria and RECIST criteria are relatively limited in their ability to assess the efficacy of such cavernous organs as esophageal cancer. After imaging, physicians also perform post-treatment “tumor pathology restaging” and pathologic biopsies to determine whether the tumor is clinically staged with neoadjuvant therapy.
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2. PET-CT.
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Before a PET-CT exam, your doctor will give you an injection of a contrast agent. This agent is similar in structure to sugar and is involved in the body’s metabolism, and tumor sites are highly metabolized, so the agent will be highly concentrated in the site and will show up on PET-CT. The report includes an “SUV value”, which is a unit of measurement of how much tracer the tumor has taken up.
A PET-CT after neoadjuvant therapy allows doctors to compare the change in SUV value before and after treatment to determine the effect of treatment.
PET-CT can be performed as early as 2 weeks after the start of the first preoperative chemotherapy, allowing for timely avoidance of ineffective neoadjuvant chemotherapy if treatment is judged to be ineffective.
3. Degree of postoperative pathological remission
As mentioned earlier, after neoadjuvant therapy, if the surgeon determines that you are ready for surgery, the surgeon will perform pathology on the excised specimen after surgery. The percentage of residual tumor on pathology is now recognized as the most accurate way to judge the efficacy of neoadjuvant therapy.