Younger rectal cancer patients don't benefit from guideline-based treatment

Last Updated: 2018-07-09

By Marilynn Larkin

NEW YORK (Reuters Health) - Adding chemoradiation to surgery, the currently recommended treatment for stage 2 and 3 rectal cancer, does not prolong survival in patients under age 50, researchers say.

"Colorectal cancer is historically considered a disease affecting the relatively elderly," Dr. Atif Iqbal of the University of Florida College of Medicine in Gainesville told Reuters Health. "Recently, however, we have noticed a rise in the number of young patients with colorectal cancer, (which) was thought to be predominantly a genetic disease."

To investigate, Dr. Iqbal and colleagues analyzed data from the U.S. National Cancer Data Base on patients treated surgically for stages 1-3 rectal cancer between 2004 and 2014. After exclusions for age (under age 20, over age 75), lack of data, different stage, receipt of adjuvant radiation, and non-receipt of chemotherapy, a total of 43,105 (out of 243,466) patients were studied.

Outcomes for patients under age 50 and over age 50 at time of diagnosis were compared based on NCCN guideline-driven treatment.

As reported online July 9 in Cancer, younger patients were more likely to be female and minorities, to be diagnosed at a higher stage, and to have traveled further to be treated at academic/integrated centers.

Patients under age 50 had significantly better outcomes in the short-term (shorter hospital stays and better 30- and 90-day mortality) and long-term (higher survival rates at three, five, seven and 10 years after treatment). There was no difference in survival by deciles up to age 50, after which prognosis worsened with each decile.

For stage 1 disease, younger patients were more likely to receive radiation treatment, which is outside of NCCN guidelines.

For stage 2 and 3 disease, younger patients were more likely to receive NCCN guideline-driven care (chemoradiation and surgical resection); however, this treatment was not associated with an overall survival benefit. In contrast, "older patients show a large and significant survival benefit from it," the authors state.

For example, younger patients treated within the guidelines had a three year-overall survival rate of 87.2%, whereas those treated outside of the guidelines had a survival rate of 85.4%. Rates for patients over age 50 were 82% for those who received guideline-driven care and 69.6% for those who did not. Similar differences between treatment groups held through 10 years.

Further age sub-stratification showed that guideline-driven care led to significantly reduced survival in patients under age 45; a statistically significant survival benefit was seen only after age 54.

"Age-specific survival data for patients with rectal cancer treated with curative intent do not support an overall survival benefit from NCCN guideline-driven therapy for stage II and III patients younger than 50 years," the authors conclude.

"The standard of care was established using previous studies that are predominantly based on patients older than 50," Dr. Iqbal said. "However, something is different about this younger group, perhaps biologically . . . We may need to treat these patients as a separate group."

"The data we're providing right now in our clinics is not accurate," he added. "Our study provides practicing physicians with the ability to offer prognosis that is personalized to the younger population."

Dr. Matthew Kalady of Cleveland Clinic, whose editorial accompanied the study, told Reuters Health by email, "One of the reasons why rates are decreasing in elderly patients is that we are doing a better job of screening for and removing precancerous lesions by colonoscopy."

"However," he said, "younger patients do not meet standard age criteria for screening recommendations, and thus asymptomatic cancers and precancerous polyps will not be found in this population."

"The age of colorectal cancer screening should be lowered, as has just been recommended, to age 45," he said. (http://bit.ly/2KJKPeJ)

"I would argue that the screening age might even be lowered to 40," he said, "as in data from our own institution, the rates are similar for patients ages 40-45 as they are for patients ages 46-50."

"Any symptoms that could be harbingers for colorectal cancers should not be ignored, regardless of the age of the patient," he stressed. "This includes patients needing to tell their physicians, and physicians investigating the complaints."

In his editorial, Dr. Kalady advises that the results be interpreted cautiously. Many patients were excluded because of missing data. Key variables such as tumor size and location were not addressed. And the study looked only at overall survival, whereas the endpoints of local recurrence and disease-free survival are typically used in rectal cancer studies.

"The conclusions that standard treatment recommendations do not benefit young patients is not warranted based on the data that is available and presented," Dr. Kalady said. "I think the more valuable information is how many patients are or are not receiving the recommended care."

SOURCE: http://bit.ly/2N2ZC0P and http://bit.ly/2N1Xzdi

Cancer 2018.