A Silent Crisis in Cancer Care: Dr. Sud Agarwal on the Future of Breakthrough Cancer Pain

In cancer care, few symptoms strike more suddenly or more cruelly than breakthrough cancer pain (BTcP). These sharp, transient flares erupt without warning, often piercing through a patient’s otherwise well-managed pain regimen. They’re intense, short-lived, and for many, deeply destabilizing.

Dr. Sud Agarwal has seen this reality up close. As a physician and medical researcher currently engaged in a number of clinical trials in pain and palliative care —not just how it behaves biologically, but how it breaks into the lives of patients already facing the weight of cancer.

“It’s misunderstood because it doesn’t behave like normal pain,” says Dr. Agarwal. “It’s episodic, fast, and hits hard. We’ve historically treated it as an extension of baseline pain, but that’s never really been accurate.”

That misalignment, he argues, has contributed to years of underdiagnosis and suboptimal treatment. While awareness of BTcP has improved, so has the urgency to act. According to recent epidemiological data, up to 80% of cancer patients with controlled background pain still experience these sudden flares. As cancer survival rates improve and the global population ages, that number is expected to rise.

From Classification to Clinical Relevance

One of the more overlooked developments in the BTcP space came not from a lab, but from the World Health Organization. In its ICD-11 classification system, BTcP was finally given its own clinical code (MG30.1). Dr. Agarwal sees this as more than symbolic.

“Classifying BTcP as a standalone condition is a major step forward,” he says. “It legitimizes the patient experience and sets the stage for tailored therapies.”

That change matters. Without it, breakthrough pain was often grouped with general cancer pain, leading to treatment plans that missed the mark. With ICD-11’s definition—including hallmark criteria like sudden onset, high intensity, and a duration typically under an hour—clinicians are now better positioned to identify BTcP and intervene accordingly.

A Therapeutic Gap Emerges

But identifying BTcP is only half the battle. Treating it effectively is another story, especially in light of recent developments. In late 2024, a quiet but significant shift took place in the drug landscape. Manufacturers voluntarily pulled all transmucosal immediate-release fentanyl (TIRF) products off the U.S. market.

These therapies, once considered the gold standard for BTcP, offered fast-acting relief in the form of lozenges, nasal sprays, and sublingual tablets. But amid mounting legal and regulatory pressures—including concerns about misuse and off-label prescribing—manufacturers exited, leaving a major gap in care.

“The withdrawal of TIRF products has put enormous pressure on clinicians,” says Dr. Agarwal. “They were the most reliable tools we had for fast-onset pain. Losing them forces us to rethink everything.”

That rethink, however, is not without opportunity. Dr. Agarwal believes this moment could usher in a more holistic and forward-thinking approach to BTcP. One that leverages technology, embraces real-world evidence, and redefines what effective relief looks like.

Rethinking Trial Design and the Role of Digital Health

Part of the challenge with BTcP is its unpredictability. Because episodes come and go so quickly, they’re notoriously difficult to track in clinical trials. Traditional pain scales often miss the nuance. That’s why Dr. Agarwal is advocating for a new paradigm: adaptive trial designs that incorporate real-time patient input.

“Pain e-diaries, wearable tech, even smartphone apps—these tools aren’t just gadgets,” he says. “They give us a live window into the patient’s experience.”

Integrating these tools, he argues, allows researchers to capture the timing, duration, and triggers of BTcP episodes with greater accuracy. It also aligns with an emerging trend in oncology: designing trials that reflect real-world use, not just controlled conditions.

What Comes Next

In the absence of TIRF drugs, many physicians have turned back to traditional opioids like morphine or hydromorphone. Others are exploring adjunct therapies—gabapentin, NSAIDs, even cannabinoids—as part of multimodal pain management strategies. But none fully replicate the speed or precision that BTcP often demands.

That’s why Dr. Agarwal is particularly interested in the next wave of investigational therapies. This includes inhalable fentanyl and non-opioid alternatives now in development. He’s also watching with cautious optimism as researchers look at neuromodulation and cannabinoid-based approaches to complement pharmacologic care.

Still, he’s quick to temper hope with realism.

“There’s no silver bullet for BTcP,” he says. “But there is a path forward. One built on better classification, smarter trials, and a deeper understanding of how these flares impact patients beyond the clinical data.”

For patients living with cancer, those flares aren’t just a medical phenomenon. They interrupt moments, milestones, and meaning. As the field moves forward, leaders like Dr. Agarwal are working to ensure that future interventions do more than treat pain. They protect dignity, restore control, and give patients back a measure of predictability in an unpredictable fight.