Calculator helps predict course of melanoma

Tool for physicians aids patient communication

Researchers at the Mayo Clinic in Rochester, MN, have developed an adjuvant systemic therapy tool, or calculator, that can help physicians and their patients better determine melanoma treatment options. Adjuvant systemic therapy uses chemotherapy drugs or hormone therapy to help destroy any cancer cells that were not removed during surgery.

"It is important for us as physicians, and specifically oncologists, to understand a natural history of disease in the people who have a cancer, who have it resected and who may be cured," says Charles Loprinzi, MD, the Mayo oncologist who led the research team.

The calculator, which incorporates a database on previous melanoma cases, indicates the relative likelihood of a positive outcome for different treatment options.

"Cancer patients have the risk of developing recurrent cancers, but there are potential drug therapies out there we can give to prevent that return," Loprinzi explains. "In that situation, it is important for us as oncologists first to know the natural history of the disease for that patient — for example, if we just did surgery alone, what the recurrence rate would be.

"Then we must understand the benefits of the actual therapy we might use," he continues. "If the truth is a person has a 70% chance to be cured with surgery alone and if we gave them chemo or interferon it would move that up to 75%, we need to understand that and tell the patient, who might then decide to go along with the therapy."

Until just a few years ago, this kind of patient-specific data — baseline prognosis and individualized benefit from therapy — had not been available to physicians, Loprinzi says.

"In order to try to better get a handle on this, several years ago, we started to look at breast cancer situations and developed a tool to better understand baseline statistics."1 All that was available at the time, he notes, were global statistics, such as 30% of the female population will develop breast cancer.

To establish a baseline prognosis, Loprinzi’s team went to expert clinicians, gave them standard information across a range of tumor types that had been seen, and asked them to provide their estimates. "We then took averages for each," he reports.

At about the same time, Peter Ravdin was developing similar baselines using what’s known as the Sear database.2

"When we went to our methods and saw what we predicted, our tool and his tool predictions were pretty close," Loprinzi notes.

The methodology used to create the breast cancer calculator was adapted to develop the melanoma calculator. "We now have better information for prognosis; it came from a recently published database," he says.

There still are some wrinkles in the system, he concedes. "For example, there is still probably some argument about the benefits of groups of patients with interferon. Some claim a 40% tumor reduction. In our tool, we say, if that’s true, this is the potential benefit that would accrue to the patient.’"

Both the breast cancer and the melanoma calculators can be downloaded from the Mayo web site (www.mhs.mayo.edu/adjuvant). Once the melanoma calculator is accessed, physicians enter information such as the depth of the tumor, lymph node status, how many lymph nodes are involved, whether they are grossly involved, and so on.

Loprinzi says tools like these can’t help but improve quality and performance.

"They will give you more accurate information for an individual patient, rather than for a population of patients," he says.

"If you have a patient with a 90% chance of doing well with surgery alone, and therapy can increase those chances by 2%, that’s a lot different than a patient with a 20% chance of doing well with surgery alone and a 30% chance of doing well with drugs. This type of information helps you make a more informed decision," Loprinzi adds.

References

1. Loprinzi CL, Thomas SD. Understanding the utility of adjuvant systemic therapy for primary breast cancer. J Clin Oncol 2001; 19(4):972-979.

2. Ravdin PM, Siminoff LA, Davis GJ, et al. Computer program to assist in making decisions about adjuvant therapy for women with early breast cancer. J Clin Oncol 2001; 19(4):980-991.

Need More Information?

For more information, contact:

  • Charles Loprinzi, MD, The Mayo Clinic, Rochester, MN. Telephone: (507) 284-8964