Is Chemo The Best Bladder Cancer Treatment For All?

DR. SCOTT TAGAWA AND DR. BISHOY FALTAS

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The bladder is a muscular organ made up of several layers of cells. This image outlines the bladder, ureters and surrounding vessels.

State-of-the-art cancer care continues to evolve due to advances in all aspects of patient care – including diagnosis, and personalized treatment and management. By incorporating novel diagnostics, systemic therapies, molecular targeted therapies, immunotherapies, and other biotechnological strategies into treatment paradigms, patient outcomes continue to improve along the cancer continuum.

For patients with bladder cancer and other urothelial cancers (cancers of the bladder, renal pelvis and ureter), cisplatin-based chemotherapy remains the standard of care. This is based on decades of research through a series of randomized clinical trials showing that chemotherapy regimens containing cisplatin consistently lead to the best overall survival rates. Importantly, some patients with metastatic urothelial cancer who are treated with cisplatin-based regimens are cured.

However, cisplatin is hard on not just the cancer cells, but the body overall. As a result, not all patients are “fit” for cisplatin. There are standard criteria that are used to define patients for whom cisplatin is not a viable treatment option. These include kidney (renal) function as measured by a blood test and sometimes urine tests, performance status (a measure of how physically functional patients are), hearing loss, nerve damage (neuropathy/numbness), and heart failure. Some of the time, there may be trade-offs. For instance, some patients would trade off the risk of needing a hearing aid for a higher chance of tumor shrinkage (or even cure).

While it is well-known among physicians that not all bladder cancer patients are candidates for this treatment option, questions linger regarding what the best treatment option should be for these patients. To get to the bottom of this question, we reviewed the scientific evidence and Dr. Scott Tagawa recently presented our findings to a large group at the 34th annual Chemotherapy Foundation Symposium (CFS). This conference brought together over 2,000 cancer care clinicians across a multidisciplinary spectrum to provide updates on the most cutting-edge new agents, ongoing clinical trials and emerging developments in cancer treatment and diagnosis.

What did the science show?

According to recent data presented at the 2016 European Society of Medical Oncology (ESMO) meeting, the most common alternative treatment regimen for patients who are well enough to tolerate chemotherapy is the combination of carboplatin and gemcitabine chemotherapies. This was based on the review of data from 1426 patients with advanced urothelial carcinoma who were treated with chemotherapy.

Interestingly, there were some other global trends in the types of chemo prescribed. Centers that treated fewer patients with urothelial cancers were more likely to give alternative (non-cisplatin) chemotherapy to patients that did not meet any standard criteria for being unfit. The most common reason for being deemed unfit for cisplatin was the patient’s current level of kidney function. Unfortunately, data showed that patients who were fit for cisplatin, but received alternative chemotherapy lived much shorter than those who received cisplatin, and none of those patients in the study were alive at the 5-year mark.

One setting where cisplatin-based chemotherapy is very important is in the pre-operative setting where the goal is cure rather than just prolongation of life by months to years. Physicians should be aware of some “tricks of the trade” to optimize kidney function and other parameters to maximize the chance for cisplatin administration and cure. For patients, it’s important to consider at least getting a consultation at a center of excellence before making a treatment decision.

We also recently wrote an editorial in The Lancet outlining the value of immunotherapy for patients with advanced urothelial cancers who are unfit for cisplatin, and in particular checkpoint inhibitor immunotherapy. While not currently FDA-approved for this indication, a study using atezolizumab (Tecentriq) was published in this prestigious journal with a second supportive study utilizing pembrolizumab (Keytruda) presented at the ESMO meeting in October. Both studies used monoclonal antibodies that enable the immune system to become activated and fight cancer, and both demonstrated substantial responses in a subset of patients. Studies of the tumor and surrounding tissue testing for PDL1 expression are able to predict those with a higher likelihood of response, but even those with “negative” testing can respond. Tests of tumor genomics are also able to group tumors into those with a higher likelihood of response, but again, even those in the lower immune responding group can have a long-term response to immune treatment. Ongoing studies are needed to help predict response in a more powerful manner. One issue that we’ve recently examined is the difference in tumor genomics before and after chemotherapy highlighted by Dr. Faltas’ high-impact publication on the clonal evolution of urothelial cancer. Among other things, this highlights the importance of obtaining recent tissue from metastatic sites to gain the most accurate understanding of an individual patient’s tumor biology.

In summary, it is important for physicians to recognize when a patient may or may not safely receive certain chemotherapy regimens, such as cisplatin combinations in the case of urothelial carcinoma. In addition, research is ongoing for patients that are unfit for certain types of chemotherapy to prove whether or not immunotherapy should be used in patients who have not yet received chemotherapy. Several immunotherapy drugs are currently being tested in randomized clinical trials and these include patients that are unfit for cisplatin. Additionally, other drugs such as antibody-drug conjugates or monoclonal antibodies have shown promising activity in patients with advanced urothelial carcinoma, and these studies included patients unfit for cisplatin.

Clotting and Cancer: What’s the Connection?

 

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Image Credit: National Cancer Institute (NCI)

What We Already Know

In the body, there is a tight relationship between cancer development and growth, treatment, and the clotting system. Cancer cells produce substances that “thicken” the blood, so men and women with cancer have a significantly higher risk of developing blood clots. On average, people with cancer are 4-7 times more likely to have blood clots than similar people without cancer. Additionally, patients with cancer being treated for blood clots with traditional anticoagulants have a higher risk of bleeding than patients without cancer.

The importance of this connection is highlighted by a dedicated conference, the International Conference on Thrombosis and Hemostasis Issues in Cancer (ICTHIC). The ICTHIC meeting features educational and scientific presentations on epidemiology, biology, prevention, and treatment of clotting and bleeding related to cancer.

The 8th meeting just took place in Bergamo, Italy. World-renowned clinicians and laboratory scientists once again met and updated colleagues. Highlights included multiple presentations and discussions about risk factors for and treatment of cancer-associated venous thrombosis, blood test-based biomarkers assessing the risk of the development or recurrence of clots, lab studies investigating the mechanisms of the tight relationship between the development, progression, and treatment of cancer and thrombosis, and clinical data regarding the treatment or prevention of blood clots in patients with cancer. Special lectures included Dr. Wolfram Ruf delivering the 4th Simon Karpatkin memorial lecture on “Targeting clotting proteins in cancer therapy” where he described years of research on tissue factors involved in cancer growth and spread (metastasis). Dr. Frederick Rickles described the history of the ICTHIC from its inception in 2001 and how the field has progressed since then with an improvement in both the science in the lab and in the treatment methods and diagnostics used in the patient clinic setting.

What’s New?

Much of this year’s conference focused on venous thromboembolism (VTE), which is most commonly manifested by deep vein thrombosis (DVT = blood clots usually in legs/pelvis) and pulmonary embolism (PE = blood clots in lungs). However, it is now clear that patients with cancer also suffer from a higher rate of arterial thrombosis, meaning that they experience a higher rate of heart attacks and stroke.

In the initial Plenary session on Epidemiology, Dr. Babak Navi, Assistant Professor of Neurology at Weill Cornell Medicine (WCM), presented data on the risk of heart attacks and stroke in women with breast cancer. In collaboration with colleagues at Memorial Sloan Kettering Cancer Center, he used data from a large database of patients with Medicare. This dataset showed that women diagnosed with breast cancer have a higher risk of a heart attack or stroke in the first year after diagnosis compared to similar women without breast cancer.

What We’ve Discovered

This year at ICTHIC, we presented data that followed up on a small pilot study presented at the 7th ICTHIC Meeting in 2014 in which Drs. Choe, Tagawa, and others from WCM’s Meyer Cancer Center and the Englander Institute for Precision Medicine utilized genomic data from men with different types of prostate cancer. Patients with advanced prostate cancer had higher expression of genes involved in coagulation and thrombosis compared to patients with early stage (localized) prostate cancer. Interestingly, patients with NEPC had different gene expression compared to patients with metastatic castration-resistant prostate cancer.

Historically, multiple studies showed that patients with cancer and blood clots had more recurrent clots compared to similar patients without cancer. This led to a change in practice starting in 2003 and now many patients use injectable medications (low molecular weight heparin) as opposed to the traditional oral medications (such as warfarin/Coumadin).

Shortly after this change in best practice, we launched a collaborative study with the University of Southern California, testing one of these injectable low molecular weight heparins (tinzaparin) for the treatment of patients with cancer and blood clots. Part of the study included regular and ongoing blood draws in order to examine the biology of the blood in these patients. In the Plenary session on the treatment of cancer-related blood clots, Dr. Tagawa from WCM and Drs. Piatek, Liebman and others from USC presented the results of this study to a global audience.

The results showed that Tinzaparin performed well when examining recurrent blood clot and bleeding rates. In addition, a blood test at the initial diagnosis of the clot called D-dimer was associated with the chance of a recurrent blood clot 6 months later. The team continues to investigate a number of additional blood test biomarkers from patients with and without blood clots in this study. We hope to be able to identify patients who are most likely to develop a blood clot and for those that do, who is most likely to have recurrence of their blood clot. In the future, this may lead to individualization of the type and/or length of treatment.

What We’re Still Trying to Find Out

WCM and other investigators continue to delve into the problem of neuroendocrine prostate cancer (NEPC), an increasingly common lethal form of the disease. Clinicians dealing with this disease believe that men with this variant of prostate cancer suffer from more blood clots than those with the more common types. However, we still don’t know whether this is related to bulkier tumors, the propensity of treating physicians to use platinum-chemotherapy (which is associated with clots), or underlying disease biology.

In addition to gaining additional insight for individual patients using biomarkers, we are also continuing to develop new drugs for the treatment of clots in patients with cancer. Several new oral agents work in patients without cancer with preliminary data in cancer patients, as well. WCM physicians are joining a global study comparing one of these new oral drugs with the standard injectable medication.

Dr. Tagawa Presents Updated Results of ATL101 at AACR

At the annual American Association for Cancer Research in Washington, DC last week, Dr. Scott Tagawa presented updated combined analysis of 4 Phase I and Phase II studies involving 114 patients treated with ATL101. The analysis demonstrated that PSMA imaging might be used to predict the response to ATL101 radioimmunotherapy.ATL101 is a new targeted radiotherapy experimental drug for treating prostate cancer. ATL101 combines the humanized J591 monoclonal antibody targeting prostate-specific membrane antigen (PSMA) plus the Lutetium-177 radioisotope, creating the first tumor-specific delivery system able to target radiation to radio-sensitive prostate cancer cells wherever they are in the body.

From the sponsor’s press release:

14 patients were evaluable for semi-quantitative analysis of planar gamma images acquired after injection of ATL101 (35 patients from phase I at dose of 10-75 mCi/m²; 47 patients from Phase II at dose of 65-70 mCi/m² and 39 patients from phase I with a fractionated schedule at dose of 40-90 mCi/m²). 22 patients were also evaluable after injection of Indium-111 labeled J591 and treatment by Yttrium-90 labeled J591 at dose of 5-20mCi/m². Patients were sorted into 3 groups: low PSMA expression group included one third of patients, with no uptake (18%) or with weakly positive images (16%); high PSMA expression group included one half of patients, with tumor image as intense (26%) or more intense (24%) than liver. The 16 % remaining patients had intermediate uptake.

Significant correlation was found between higher PSMA expression (high vs. low) and higher response rates (RR) to treatment defined as >30% decline in PSA (RR=32% vs. 12.5%, p=0.01). RR was itself significantly correlated to longer survival. An association between PSMA expression by imaging and reduction in circulating tumor cell counts was also found (p=0.07). Further studies will examine quantitative molecular imaging with anti-PSMA PET/CT as recently published in animal models (Morris et al, 2013 ASCO Genitourinary Cancers Symposium).

Click here to read the complete press release.