Follow-up Care for Renal Mass Patients Requires Attention to Both Kidney Function and Cancer Recurrence

After treatment for a renal mass, patients require two types of follow-up: functional and oncological. Protocols for the former are well-defined, but protocols for the latter are still being debated.

Because urologic oncologists spend so much time following such patients in clinic, it’s important for physicians to understand the issues and evidence associated with each type of surveillance. That was the message that Steven Campbell, MD, PhD, Section of Urologic Oncology, Glickman Urologic and Kidney Institute, delivered at the American Society of Clinical Oncology 2018 Genitourinary Cancers Symposium.

“As urologists, 50 percent or more of what we do in clinic every day is follow patients who we have treated in the past, both in terms of kidney function and cancer monitoring,” Dr. Campbell says. “Much time, energy and cost goes into this. On the oncologic side especially follow-up can be very expensive because of the imaging involved. It can also be anxiety-provoking for patients and a challenge for physicians because of ongoing controversies about the best surveillance methods.”

Radical nephrectomy and inferior vena cava thrombectomy for locally advanced renal cell carcinoma.

Kidney function follow-up is relatively straightforward

Most patients who are treated for a localized kidney mass do not die of cancer, Dr. Campbell says, citing statistics from EORTC 30904, a well-known clinical trial, in which only 12 out of 545 patients (2.8 percent) died of kidney cancer in the 10 years after their mass was resected.

Patients with healthy kidneys at the time of surgery usually do well functionally after resection. They experience only 0.7 percent kidney decline each year, which is consistent with the aging process, even if they develop mild chronic kidney disease (CKD) after surgery, Dr. Campbell notes. However, if patients have pre-existing CKD prior to surgery, they tend to not fare as well after having a mass removed. Studies have shown these patients experience renal decline of 4.7 percent a year.

“Many cancer patients have good kidney function before we operate,” he continues. “We then do a partial nephrectomy where we save most of the kidney. They move on in life with 1.8 kidneys, and most have normal function,” Dr. Campbell explains. “However, some patients with CKD start out with poor kidney function, then we operate and remove a portion of the kidney, and their function falls even further.” All patients, he adds, should be followed with serum creatinine (SCr)-based estimated glomerular filtration rate (GFR) and urinalysis. If the dipstick shows greater than trace proteinuria, a creatinine/albumin ratio should be obtained.

With this in mind, Dr. Campbell notes, there are several indications that a patient is at risk for kidney decline, and these patients should be referred to a nephrologist:

• If they are left with less than 50 percent of a single kidney after surgery
• If they had CKD prior to surgery, particularly if they are diabetic or if their preoperative GFR was less than 45 ml/min/1.73 m2
• If they have a GFR of less than 30 ml/min/1.73 m2 after surgery — which translates to stage 4 CKD
• If they have confirmed proteinuria, which often warrants a 24-hour urine analysis to more accurately quantify the condition

Partial nephrectomy for management of localized renal cell carcinoma. Figures reprinted with permission from Elsevier (Rini BI, Campbell SC, Escudier B. Renal cell carcinoma. Lancet. 2009;373[9669]:1119-1132). Copyright ©2009 Elsevier.

Oncologic surveillance: controversial, more challenging

Follow-up care for renal mass patients also includes monitoring for cancer recurrence. This requires continual surveillance that is costly and can make patients anxious, Dr. Campbell says, because they fear both learning their cancer has returned and repeated radiation exposure during x-rays and scans.

Intensive imaging surveillance is also controversial because there is no evidence yet that such methods improve patients’ survivorship, Dr. Campbell notes. Unlike with colon cancer, where randomized trials have shown that intensive surveillance improves overall survival, good data to guide physicians in kidney cancer follow-up surveillance does not exist.

In general, he says, patients who have a localized recurrence amenable to salvage or completion nephrectomy, or very limited systemic recurrence such as a solitary pulmonary nodule and no evidence of other metastases, are the best candidates for further treatment. Clinical experience suggests they are the most likely to survive cancer-free. He also points out that competing causes of death may mean that elderly patients don’t need as much surveillance because they are more likely to die of old age or other disease processes than cancer recurrence.

Many guidelines

Another problem urologists face in oncological surveillance is choosing among four different sets of guidelines, each from prominent organizations in the field. While all are evidence-based and use risk stratification, available evidence is not rigorous and they come to different conclusions, Dr. Campbell explains. Some call for only three years of surveillance, some for lifetime surveillance. Some advocate for chest x-rays; some for CT scans of the chest. Some stratify by algorithm and some by stage and treatment modality.

Dr. Campbell’s preference are American Urological Association (AUA) guidelines, which he describes as sensible and simple: “The AUA guidelines process is very rigorous and their guidelines seem to make the most sense.”

The situation provides leeway for physician acumen based on individual patient risk profiles. “Physicians have to consider each case on an individual basis,” he concludes, “and proceed using their best judgment.”