Leading expert in colorectal surgery, Dr. Torbjorn Holm, MD, explains how radiation therapy for rectal cancer is a powerful tool for locally advanced tumors but should be avoided for early-stage cancers to prevent significant short-term and long-term complications. He details the evolution of rectal cancer treatment from high recurrence rates to the modern approach of combining total mesorectal excision surgery with selective preoperative chemoradiation, which has reduced local recurrence risks to below 5%.
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Optimizing Rectal Cancer Treatment: When Radiation Therapy Is Necessary
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- History of Rectal Cancer Treatment
- Impact of Radiation Therapy on Recurrence
- Role of TME Surgery
- Modern Treatment Approach
- Identifying Candidates for Radiotherapy
- Risks of Radiation Complications
- Importance of Treatment Selection
History of Rectal Cancer Treatment
Dr. Torbjorn Holm, MD, provides critical context on the history of rectal cancer care. He notes that treatment outcomes were poor internationally until the mid-1990s. The risk of a local recurrence, where cancer returns in the pelvis after surgery, was alarmingly high at 25% to 30% even when surgeons believed they had performed a radical operation.
This high failure rate prompted the initiation of clinical trials in Stockholm in the 1980s. The goal was to find ways to improve these dismal results and reduce rectal cancer recurrence rates through new strategies like radiotherapy.
Impact of Radiation Therapy on Recurrence
The Swedish rectal cancer trials represented a major advancement in oncology. Dr. Torbjorn Holm, MD, explains that these studies randomized patients to either surgery alone or preoperative radiation therapy followed by surgery.
The results were transformative. Giving radiation therapy before surgery reduced the risk of local recurrence by 50%. This dropped the recurrence rate from approximately 25% down to about 12%, proving the efficacy of neoadjuvant radiotherapy for rectal cancer.
Role of TME Surgery
A subsequent surgical breakthrough further revolutionized care. Dr. Torbjorn Holm, MD, highlights the contribution of Professor Bill Heald, who pioneered the technique of total mesorectal excision (TME).
This meticulous surgical method involves removing the entire mesorectum, the fatty tissue surrounding the rectum that contains lymph nodes. Combining TME surgery with radiation therapy produced even more dramatic results, slashing local recurrence rates to less than 5%.
Modern Treatment Approach
The modern paradigm for treating rectal cancer has evolved significantly. Dr. Torbjorn Holm, MD, describes a more nuanced approach. The pendulum has swung from believing every patient needed radiotherapy to understanding that high-quality surgery is the cornerstone of treatment.
For early-stage, superficial tumors that are easy to resect, surgery alone is often sufficient. This shift avoids unnecessary exposure to radiation and its associated toxicities for patients who can be cured with operation alone.
Identifying Candidates for Radiotherapy
Radiation therapy remains essential for a specific subset of patients. Dr. Torbjorn Holm, MD, clarifies that it is indicated for locally advanced rectal cancer.
This includes tumors that invade the mesorectal fascia or cases with several lymph nodes involved with cancer. For these patients, preoperative radiotherapy is often combined with chemotherapy (chemoradiation) to shrink the tumor before surgical resection, improving the chances of a successful outcome.
Risks of Radiation Complications
The power of radiation comes with a significant cost. Dr. Torbjorn Holm, MD, emphasizes that radiotherapy can induce both early and late complications.
Short-term side effects can include skin irritation, fatigue, and diarrhea. Long-term complications are more serious and can include chronic bowel and bladder dysfunction, sexual dysfunction, and even secondary cancers. This is why avoiding unnecessary treatment is a core principle.
Importance of Treatment Selection
Selecting the right treatment for each individual is paramount. Dr. Torbjorn Holm, MD, concludes with a guiding principle: radiation is a powerful tool for advanced cases, but if you don't have to use it, you shouldn't.
This underscores the importance of a accurate initial diagnosis and staging. A medical second opinion can be invaluable to confirm the cancer stage and ensure the treatment plan—whether it involves surgery alone or multimodality therapy with chemoradiation—is the best and most appropriate option for the patient.
Full Transcript
Dr. Anton Titov, MD: When does radiation therapy help rectal cancer patients? When is radiotherapy useless? Does radiotherapy only induce toxicity? How should radiotherapy be used correctly in rectal cancer?
Dr. Torbjorn Holm, MD: Again, we have to remember our history. Rectal cancer treatment was not good in Sweden and internationally until the mid-1990s or late 1990s. We have to remember that the risk of local recurrence of rectal cancer was about 25% to 30%, even though rectal cancer surgeons thought they had done a radical operation. Local recurrence means that rectal cancer comes back in the pelvis after the operation.
The risk of rectal cancer recurrence was very high. In 1980, we started a clinical trial in Stockholm to learn how we could improve rectal cancer recurrence rates. We started clinical trials of radiotherapy in rectal cancer. Then we started the Swedish rectal cancer trials. We randomized rectal cancer patients to have surgery directly; other patients had radiation therapy for rectal cancer followed by a surgical operation.
We did rectal cancer clinical trials because surgical treatment results were so poor. We could show that giving the patient with rectal cancer radiation therapy before surgery reduced the risk of local recurrence of rectal cancer by 50%. So the risk of rectal cancer coming back locally after surgery went from about 25% down to maybe 12% after the patient had preoperative radiotherapy for rectal cancer.
But then Professor Bill Heald taught us how to do total mesorectal excision for rectal cancer. Then we showed that combining radiation therapy with total mesorectal excision of rectal cancer reduced local recurrence rates to less than 5%. Then we reassessed our rectal cancer treatment options.
We now think that the most important option to treat colorectal cancer is a surgical operation. Sometimes you do good surgery for rectal cancer, and then you don't need radiation therapy. This is especially true for rectal cancer that is discovered at an earlier stage. So the pendulum has come back again.
Before, we thought that every rectal cancer patient had to have radiation therapy before a surgical operation. Now we realize that with good surgery, you don't need to give radiotherapy to everybody with rectal cancer. You need to give radiation therapy to some rectal cancer patients who have locally advanced rectal cancer.
Today, the practice of treating rectal cancer is this. Sometimes you have a more advanced rectal cancer that invades the mesorectal fascia, or you have several lymph nodes involved with colorectal cancer. Then you should give the rectal cancer patient radiotherapy. Often you have to combine radiation therapy with chemotherapy, and then you do rectal cancer surgery after chemotherapy and radiation therapy.
Some patients have a superficial rectal cancer tumor that could be easy to resect. Then the cancer surgeon does not need to give the rectal cancer patient radiation therapy, because radiation therapy for rectal cancer can also induce a lot of complications.
Dr. Anton Titov, MD: Complications after radiation therapy for rectal cancer can be both early complications and late complications.
Dr. Torbjorn Holm, MD: Radiation therapy is a powerful tool for the advanced rectal cancer cases. But if you don't have to use radiotherapy, you shouldn't do it, because radiation therapy can give complications to colorectal cancer patients in the short term and in the long term.