Big Bang Theory Actress Kate Micucci Discloses Lung Cancer Diagnosis Without Smoking—What Could Have Caused It?

Kate Micucci, famed for her role in “The Big Bang Theory”, is battling lung cancer, as revealed by a TikTok video she posted on Tuesday.

In the video, Micucci, 43, informs her followers, “Hey everyone, this isn't a TikTok, it’s a ‘sick tok’. I’m hospital-bound at the moment following a lung cancer surgery I had yesterday.”

Micucci reveals her care team discovered the cancer early on, nevertheless, the diagnosis was surprising. She states it's strange because she has never smoked in her life and yet, it happens.

Even though approximately 80% of lung cancer incidences relate to smoking, non-smokers are being diagnosed more often recently.

According to estimates by the Centers for Disease Control and Prevention (CDC), up to 20% of the annual lung cancer incidences in the US affect non-smokers or those who have smoked less than 100 cigarettes throughout their lives.

Lung cancer specialist and thoracic surgeon at Moffitt Cancer Center, Lary Robinson, MD, described the situation as disturbing. He recalls how twenty years back, a lung cancer case in a non-smoker would have been noteworthy while today he gets at least one such case weekly.

Earlier research this year revealed that lung cancer rates are higher in younger, middle-aged women than in men of the same age. The reasoning behind this remains unclear.

While smoking cigarettes, pipes, or cigars are primary risk factors for lung cancer, they aren't alone. Other risk factors comprise of secondhand smoke, radon, air pollution, asbestos, and congenital predisposition to lung cancer.

Researchers estimate that secondhand smoke and radon exposure contribute to around 7,300 and 2,900 lung cancer diagnoses annually, respectively. The increased lung cancer incidence in non-smokers is still a mystery.

While radon exposure has been a known risk for years, Robinson argues that it's unlikely that radon exposure has increased in the last 50 years. He suspects an environmental root cause but more research is needed, especially regarding lung cancer rates in women non-smokers.

Dr. Jack Jacoub, MD, currently investigating causes ranging from estrogen metabolites, chronic inflammation, processed foods, and chemicals, expresses uncertainty about these factors' role in augmenting lung cancer risk.

Lung cancer in non-smokers displays unique characteristics compared to that in smokers. It usually appears and ages younger, potentially harboring distinctive genetic changes. Non-smokers typically present with non-small cell lung cancers, specifically adenocarcinoma, which forms in the lung's mucus-producing cells.

About 10%-20% of cancers in non-smoking people are squamous cell carcinomas that form within the lung's internal airway linings. Both types of cancers can cause similar symptoms.

The prognosis for a non-smoking person diagnosed with lung cancer depends on the stage at which it's detected. However, diagnosis often comes late due to the lack of recommended screening for non-smokers, leading to poorer outcomes.

On the other hand, early detection vastly improves a non-smoker's chance of survival. Dr. Jacoub attributes this to the fact that non-smokers tend to be healthier and younger without other chronic smoking-related issues like heart and lung diseases.

Additionally, nonsmokers with lung cancer may experience less severe implications due to the unique mutations causing their cancers. According to Dr. Robinson, "the saving factor for many never-smoking patients with lung cancer is that they tend to have mutations that we have drugs for. We have a lot of targeted agents to help.”

More research is needed to determine what’s causing lung cancer in people without a history of smoking.

Researchers believe staying away from secondhand smoke, air pollution, radon, and other cancer-causing agents (asbestos, arsenic, diesel exhaust) can help reduce nonsmokers’ risk of lung cancer.

More general cancer prevention methods may help, too, though they’re not guaranteed.

“I could stand on my soapbox and say the best thing to do to lower your risk of lung cancer if you don’t smoke is to maintain a normal weight, eat a healthy diet, and exercise,” said Robinson. “If you did that, you would lower your risk of a lot of different cancers and diseases, but that’s not a guarantee.”

Some risk factors, however—like a personal or family history of the disease—cannot be changed. It’s for this reason that experts recommend everyone know or become aware of their family history, which can also be a preventative measure.