Reevaluating Treatment for Penile Cancer to Avoid Surgery

Because developments are lacking in systemic therapy for the treatment of patients with stage 3 or higher penile cancer, a trial in this patient population may provide a glimpse into the most effective treatment sequence.

The InPACT trial, which is currently enrolling patients in the U.S., Canada and U.K., aims to find an improved way to cure this rare cancer; penile cancer affects less than 1% of patients with cancer, according to the American Society of Clinical Oncology. Approximately 2,210 men in the United States will receive a diagnosis of penile cancer in 2021, with an estimated 460 men dying from the disease this year.

“Metastatic penile cancer is a potentially fatal cancer but also potentially curable,” Dr. Lance C. Pagliaro, a consultant in the division of medical oncology and professor of oncology at Mayo Clinic in Rochester, Minnesota, told CURE®. “We look at strategies to combine different treatment modalities — surgery with chemo- therapy or radiation with chemo — to control and ultimately cure the largest percentage of patients that we can.”

For the past 10 years, the standard of care in these patients has been cisplatin-based chemotherapy. The InPACT study is historic because it is the first randomized clinical trial for this disease, with patients placed into groups to allow researchers to compare different treatments. Researchers will assess one of three treatment sequences in patients with penile cancer that’s stage 3 or higher (indicating spread to the lymph nodes in the groin and/or pelvis):

• Upfront surgery to the lymph nodes.
• Neoadjuvant (or preoperative) chemotherapy, followed by surgery (representing the current standard treatment regimen).
• Neoadjuvant chemoradiotherapy, followed by standard surgery.

“Patients come to us with different extent of disease,” said Pagliaro, who is also a principal investigator for the trial at Mayo Clinic. “Whether it’s one lymph node involved or multiple lymph nodes in the groin or lymph nodes in the pelvis greatly impacts the chance of cure and the risk of death. The researchers of the InPACT trial aim to help us understand how to calibrate the treatment to what the patient needs.”

Although surgery upfront and surgery after chemotherapy are not technically new treatments, chemoradiation followed by surgery is a new approach that is “not normally done,” Pagliaro said. “It’s a new approach because you’re combining all three (chemo, radiation and surgery), and one of the purposes of trial is to find out what is the safety and if there are any downsides to giving radiation prior to surgery, as well as potential upsides.”

Assessing the sequence of treatment for penile cancer may also help researchers define the role of surgery to the lymph nodes in the pelvis. Although removing all lymph nodes in the pelvis is current standard of care, it may subject some patients to an unnecessary procedure.

“The InPACT trial seeks to answer that question by randomizing patients to either pelvic lymph node dissection, preventive radiation or, in some cases, observation if they have a favorable response to their initial treatment,” Pagliaro said. “That’s a way of achieving the same outcome with less-invasive treatment.”

Pagliaro explained that even though this trial will provide more insight into the treatment
of penile cancer, oncologists can still effectively treat patients while awaiting results, which could take three to five years to analyze.

“If there has been spread to one or more lymph nodes, it’s not a hopeless situation,” he said. “Penile cancer is a disease where we can cure some of those patients and have done for years with surgery alone, but what we’re trying to do by combining surgery with radiation and/or chemotherapy is to cure a larger percentage of those patients with limited spread of disease.”

Patients with symptoms potentially indicating penile cancer should see a doctor immediately.

“We do see cases of men who are embarrassed or just don’t want to deal with it,” Pagliaro said. “Allowing time for cancer to spread and grow is not a good thing. So I encourage men that have any kind of symptom or concern to get checked out right away.”

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