Most colon cancers are straightforward to treat, but rectal cancer is highly complex and requires more specialized expertise.
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"Rectal cancer is very difficult to treat. It's a complicated disease, and if not done right it can be devastating," says Karin Hardiman, M.D., Ph.D., surgical director of the Multidisciplinary Colorectal Cancer Clinic at the University of Michigan Comprehensive Cancer Center.
In advanced rectal cancer, organs beyond the rectum become involved, either because the primary tumor is large and invades nearby areas or because it has spread to the liver or another organ. Historically, many of these patients were sent home to die.
Even for early stage disease, rectal cancer recurs in up to 40 percent of patients. Then survival rates plummet to 10 percent.
That's why getting treatment right the first time is essential — and why a multidisciplinary care team and personalized approach are key.
Further, ongoing clinical trials available at Michigan Medicine and other cancer centers are seeking to determine the best treatment for each rectal cancer patient.
Imaging quality affects treatment
The first step is imaging, which is critical for oncologists to stage the cancer and develop a treatment plan. MRI provides more accurate results than CT scans but requires a precise patient alignment. And that's where it gets tricky, as rectum tilt varies from patient to patient.
"Imaging in rectal cancer is essential," says Mahmoud Al-Hawary, M.D., a radiologist with the Comprehensive Cancer Center's colorectal clinic. "For most accurate results, it's important that the strongest MRI magnets are used, scanning technique is optimized and the patient is appropriately positioned in the scanner."
With these optimized MRIs, oncologists can more accurately stage the cancer and recommend the appropriate treatment. For example, if surgeons can see tumor deposits away from the primary tumor site — which indicates a high chance of metastasizing to lung and liver — they can plan to remove that tissue during the operation.
Complex surgeries require multiple specialists
Even with the best imaging, operating on rectal cancer is a delicate endeavor. Tumors are often large and may be multi-visceral, meaning they extend into multiple organs.
SEE ALSO: What Primary Care Doctors Should Know About Colorectal Cancer Care
It's a high real-estate area, Hardiman points out. Many critical daily functions sit within the pelvis. Rectal cancer treatment, as a result, can cause significant impact on important quality-of-life issues, leaving patients with ostomies, incontinence and sexual dysfunction.
Many patients need pre-operative treatment with chemotherapy and radiation to shrink the tumor and prevent local and distant recurrence in the future.
For the tumor resection, involving multiple specialists — including colorectal, hepatobiliary, gynecologic and urologic oncologists, as well as spine and plastic surgeons as needed — is key. A multidisciplinary team can remove tumors that would have been considered inoperable for a colorectal surgeon alone while also preserving a patient's quality of life.
In some women, the tumor might extend into the vagina and uterus, in which case gynecologic oncology surgeons and plastic surgeons are called in to assist with the resection and reconstruct the area.
"If that reconstruction is not done, they'll have no sexual function in their future," Hardiman says. Similarly, she adds, urologic oncologists can help ensure urinary function.
Clinical trials look to improve treatment
Depending on their tumor, rectal cancer patients are typically treated with surgery, chemotherapy and radiation — an aggressive treatment approach that has evolved to help limit recurrence.
But does everyone need the three-pronged assault?
Two clinical trials, both currently offered at Michigan Medicine, will look at whether some patients can receive less-aggressive treatment and still achieve good outcomes.
Organ Preservation in Rectal Adenocarcinoma will examine whether chemotherapy plus radiation without surgery may be sufficient for patients with locally advanced rectal cancer. After receiving chemotherapy and radiation, patients will be observed through imaging, endoscopy and exams. Those that enter a complete remission will not have surgery. In smaller studies testing this approach, 20 percent of patients were able to avoid surgery.
"It's an ongoing challenge to see who is going to have a complete response to chemo-radiation, and how long do you wait to tell whether the patient is responding. This trial is designed to shed some light on these questions," says John Krauss, M.D., medical director of the Comprehensive Cancer Center's colorectal clinic.
A second trial, PROSPECT, is open at cancer centers throughout the country. It will evaluate whether some patients with locally advanced rectal cancer can skip radiation therapy. Radiation therapy has been shown to decrease the risk of cancer returning in the pelvis, but some patients experience severe side effects.
"We are trying to understand how to personalize the treatment we give patients so that they have the lowest risk of recurrence with the least toxicity and the least impact on quality of life," Krauss says.
To learn more about rectal cancer clinical trials, both patients and physicians should call the Comprehensive Cancer Center's Cancer AnswerLine at 800-865-1125.