This article is more than 5 years old. Information may no longer be current.
Second malignancies, death common among cancer survivors
Click Here to Manage Email Alerts
Approximately one in 12 patients with a common primary tumor were diagnosed with a second primary malignancy between 1992 and 2008, according to results of a SEER analysis.
Further, more than one-half of these patients died of their second malignancy. Lung cancer was the most common second primary malignancy.
Nicholas Donin
“We observed in our urologic oncology clinic that several of our patients with bladder cancer were incidentally found to have second primary lung tumors,” Nicholas Donin, MD, urologic oncology fellow at UCLA’s David Geffen School of Medicine, told HemOnc Today. “After observing this several times, we thought it might be interesting to investigate how common this was, and we wanted to expand this to all patients with common cancer types. We were aware that second primary cancers are becoming more common, as survival from cancer is improving over time.”
Multiple primary cancers comprise approximately 17% of all incidence cancers, and cancer survivors may face an increased risk for second malignancies, due to late treatment effects or genetic predispositions.
Donin and colleagues used the SEER database to identify individuals diagnosed with a primary malignancy of the 10 most common cancer sites — breast, prostate, lung, colon, rectum, bladder, uterus, kidney, melanoma and non-Hodgkin lymphoma — between 1992 and 2008.
The study included data from patients with various disease stages, including in situ disease, clinically localized disease, locally advanced disease and metastatic cancer.
The researchers excluded patients diagnosed with a second malignancy in the same site as their primary malignancy, as well as those diagnosed with a second malignancy within 1 year of their primary diagnosis.
The diagnosis of a second primary malignancy served as the study’s primary endpoint. Death caused by the second malignancy served as the secondary outcome measure.
The study included data from over 2.1 million patients (51.8% men; 82.7% non-Hispanic white; 37% diagnosed between the ages of 66-80 years). Prostate (28.1%) and breast (23.2%) were the most common primary tumor sites; 62.9% of patients had in situ or localized disease.
After a mean follow-up of 7.09 years (standard deviation, 4.26), 8.1% (n = 170,865) of the cohort experienced a second primary malignancy.
Sixty percent of second malignancies developed in patients aged older than 65 years. Survivors of breast, prostate, colon and bladder cancer comprised 73% of individuals diagnosed with a second malignancy.
Bladder cancer survivors exhibited the highest risk for second cancers, with 19% diagnosed with a second malignancy at 10 years and 34% diagnosed at 20 years. Survivors of lung, prostate, colorectal and kidney cancers also experienced poor rates of cancer-free survival.
Lung cancer served as the most common second malignancy (18%), followed by colorectal cancer (12%), prostate cancer (9%) and bladder cancer (8%).
“Lung cancer is an extremely common cancer in general,” Donin said. “It is the second most diagnosed cancer in women and men, and it is associated with smoking. Smoking is also an incredibly common risk factor for a number of cancers — including bladder, prostate, colon and cancers of the oral cavity — which likely explains why cancers related to smoking are common second malignancies.”
The researchers observed a high incidence (25%) of secondary lung cancers in survivors of bladder cancer. Secondary breast cancers occurred frequently in survivors of endometrial (30.4%) and thyroid (23.9%) cancers.
A multivariate analysis that controlled for age at diagnosis, sex, race, marital status, tumor grade, educational level and household income found that male and female survivors of non-Hodgkin lymphoma had the highest risk for a second malignancy (men, HR = 2.7; women, HR = 2.88), followed by bladder cancer (men, HR = 1.88; women, HR = 1.66) and kidney cancer (men, HR = 1.86; women, HR = 1.53).
Among women, those aged 66 to 80 years had the highest risk for second malignancy compared with the youngest, or those aged 18to 35 years (HR = 7.13; 95% CI, 6.63-7.65). Men aged older than 80 years had the highest risk (HR = 15.24; 95% CI, 13.47-17.23).
Thirty-six percent (n = 771,150) of the entire study cohort died, of whom 54% died of their first or second malignancy. Fifty-two percent of patients with only one cancer died of their malignancy.
Among patients with two or more malignancies, 13% died of their initial cancer and 55% died of their second primary cancer.
Second primary lung cancer accounted for a greater number of deaths (n = 17,223; 12%) than all cases of melanoma, bladder cancer, thyroid cancer, kidney cancer or endometrial cancer.
The researchers acknowledged study limitations, including the potential for misclassifying primary tumor metastases as second malignancies. They also were unable to capture possible cancer risk factors, such as smoking, alcohol use or obesity, which are not recorded in the SEER database.
“Level-one data from the National Lung Screening Trial clearly demonstrates that screening for lung cancer saves lives,” Donin said. “If you encounter a patient who meets the inclusion criteria for this trial, virtually every professional organization and society dealing with this area of medicine recommends three annual spiral chest CTs. It behooves all physicians to be familiar with this trial and the patients who meet the inclusion criteria.
“Second primary lung cancer kills more people each year than melanoma, bladder cancer, kidney cancer, thyroid cancer and endometrial cancer,” Donin added. “That’s a significant mortality contribution, and efforts to detect and combat the disease will save lives.” – by Cameron Kelsall
For more information:
Nicholas Donin, MD, can be reached at ndonin@mednet.ucla.edu.
Disclosure: The researchers report no relevant financial disclosures.
Click Here to Manage Email Alerts