If you’ve achieved lung cancer remission, you may worry that your cancer may return. Some people are also at risk of developing an entirely new cancer — like lung cancer — later on. This is known as a second primary cancer, and certain factors raise your risk of developing it. People who have been diagnosed with specific types of cancer are more likely to develop lung cancer later on.

Keep reading to learn more about lung cancer development after another cancer and what factors play a role. We’ll also cover how developing a second primary cancer affects your prognosis (outlook). To learn more about your risk of lung cancer after another cancer, talk to your doctor or oncologist (cancer specialist).

What Is a Second Primary Cancer?

According to the American Society of Clinical Oncology, a second primary cancer refers to “a completely new and different type of cancer than the first one.” This is different from cancer recurrence, which means your first cancer has returned and started growing again. A recurrence can develop in the same location it was in before or in a completely different spot.

Unfortunately, it’s impossible to predict who will go on to develop a second primary cancer. We’ll cover some of the factors known to play a role in this cancer’s development.

Lung Cancer as a Second Primary Cancer

If you’ve been previously diagnosed and treated with another type of cancer, you may be at risk of developing lung cancer. It’s important to note that this article won’t be covering:

• What happens if your first lung cancer returns after you’ve been in remission
• Secondary lung cancer, or other types of cancer that have spread from one organ to the lungs

Lung cancer is divided into two types: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). NSCLC is the most common type of lung cancer. It can be divided into subtypes, including adenocarcinoma and squamous cell carcinoma.

One study in the journal Frontiers in Oncology looked at more than 5,000 people with multiple primary cancers (MPCs) — those who have at least two types of cancer at the same time. The authors found that people with MPCs were more likely to develop certain lung cancer subtypes. They found that:

• Adenocarcinoma accounted for 37.8 percent of lung cancer cases
• Squamous cell carcinoma accounted for 22.3 percent of cases
• SCLC accounted for 9.3 percent of cases
• Other lung cancer subtypes accounted for 30.6 percent of cases

What Primary Cancers Can Lead to Lung Cancer?

Research shows that people with certain types of primary cancer are more likely to develop lung cancer as a second primary cancer. The same study of more than 5,000 people with MPC looked at the most common cancer sites associated with second primary lung cancer (SPLC). The five most common cancers included:

• Prostate cancer
• Female breast cancer
• Urinary bladder cancer
• Laryngeal cancer, which affects your larynx or voice box
• Non-Hodgkin lymphoma, a type of blood cancer

Another study published in the British Journal of Surgery found that people with esophageal cancer, head and neck cancer, or anal cancer are at an increased risk of lung cancer.

Lung Cancer Survivors Can Also Develop a Second Primary Lung Cancer

You may also be at risk of developing an SPLC if you’ve already had lung cancer. This means that you develop an entirely new type of lung cancer unrelated to your first lung cancer.

One study looked at records from the National Cancer Institute database of people who were diagnosed with primary lung cancer. They found that more than half of people with SPLC were diagnosed within five years of their first lung cancer diagnosis. Another 7.4 percent developed SPLC within 10 years.

Risks Associated With Developing Second Primary Lung Cancer

Certain risk factors can influence your chance of SPLC.

Side Effects of Previous Cancer Treatment

Radiation therapy — also known as radiotherapy — is associated with a higher risk of certain cancers. Radiation treatment uses high-powered beams of radiation to damage the DNA inside cancer cells. This helps shrink tumors and relieve your symptoms. However, radiation can also damage the healthy cells around your tumor.

People who had initial treatment with radiation therapy to the chest are more likely to develop SPLC after treatment.

Time Between Developing First and Second Cancers

Researchers have also looked into how long it typically takes to be diagnosed with SPLC after a first primary cancer diagnosis. In the Frontiers in Oncology study of people with SPLC, the median times between diagnoses were:

• Prostate cancer — 26 months
• Female breast cancer — 52 months
• Urinary bladder cancer — 24 months
• Laryngeal cancer — 9.5 months
• Non-Hodgkin lymphoma — 17.5 months

The median time refers to the amount of time it took for at least 50 percent of people with a certain type of cancer to develop SPLC. This means that it took 26 months for at least half of the individuals in the study with prostate cancer to develop lung cancer.

Age

Generally speaking, cancer tends to affect older adults. Older cells are more likely to become damaged and turn cancerous.

Most people with SPLC are above the age of 65. In the Frontiers in Oncology study, more than 72 percent of participants were ages 65 and above. Although you can’t slow aging, you can take extra steps to live healthier and lower your cancer risk.

Smoking

You likely know that smoking negatively affects your lung health and increases the chances of lung cancer. Studies show that smoking is also a significant risk factor for SPLC. Luckily, quitting smoking can reduce your cancer risk over time.

Genetic Syndromes

Some families have certain gene mutations (changes) that raise the risk of cancer. These mutations are passed down from parents to their children. Genetic cancer syndromes like Li-Fraumeni syndrome are associated with the development of several types of cancer, including:

• Lung cancer
• Breast cancer
• Soft tissue sarcomas, which develop in the muscles, bones, or fat tissue
• Leukemia, a type of blood cancer

Prognosis of Lung Cancer as a Second Primary Cancer

Researchers have found that having SPLC is linked to shorter survival rates. One report from the Journal of the National Cancer Institute looked at more than 12,000 people with this cancer type. The authors found that those with second primary cancer were twice as likely to die within a given period compared to those with only a single primary lung cancer.

Keep in mind that studies can’t predict exactly what will happen with your specific cancer case. Your outlook with SPLC depends on several factors.

Talk to Your Doctor About Your Risk of Further Cancers

If you’re a cancer survivor and are concerned about your risk of developing other primary cancers, talk to your oncologist. They can go over your risk factors to help you better understand your outlook. Your oncologist can also recommend healthy lifestyle changes and offer their support. You’ll also want to attend long-term follow-up appointments to monitor your overall health and any new symptoms you develop.

Preventive screenings are also available for people at a high risk of lung cancer. You can call your cancer care team’s office to learn more about these screenings and schedule an appointment. Early detection is key to treating your cancer and improving your outlook with a second malignancy (cancer).

Talk With Others Who Understand

MyLungCancerTeam is the social support network for people with lung cancer and their loved ones. On MyLungCancerTeam, more than 13,000 members come together to ask questions, give advice, and share their stories with others who understand life with lung cancer.

Have you developed lung cancer as a second primary cancer? What cancer type were you initially diagnosed with? Share your experience in the comments below, or start a conversation by posting on your Activities page.