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Needle biopsy of suspicious lung nodules, initially detected by CT scan, isn't as benign as often thought, according to a population-based study that quantified the risks in community practice.

Needle biopsy led to clinically-significant hemorrhage for 1% of patients and pneumothorax for 15%, Renda Soylemez Wiener, MD, MPH, of Boston University School of Medicine, and colleagues found.

Pneumothorax severe enough to require a chest tube occurred with 6.6% of biopsies, the group reported in the Aug. 2 issue of the Annals of Internal Medicine.

"Complications do occur more commonly than many people realize," Wiener said in an interview with 番茄社区.

Smokers and those with chronic obstructive pulmonary disease (COPD) were at particularly high risk of complications in the study.

"For many patients, including those with a low risk for cancer, those who are too frail to undergo cancer treatment, or those with a high risk for cancer who should proceed directly to surgery, this procedure may be unnecessary," the group warned in the paper.

Smokers are one high-risk group for whom lung biopsy is an increasingly common issue.

Annual CT screening for lung cancer got a boost from the National Lung Screening Trial last year with evidence that it saves lives among smokers.

But CT finds pulmonary nodules in up to one-quarter of patients -- far more than actually have cancer -- and conclusively figuring out which are true cases requires invasive biopsy.

"Before exposing patients to potential harm from CT-guided biopsy, physicians must ensure that patients understand the risks," Wiener's group noted.

How big those risks were had been known only from selected centers' case series, so the group did a cross-sectional analysis of hospital discharge records from the 2006 State Ambulatory Surgery Databases and State Inpatient Databases for California, Florida, Michigan, and New York.

Those databases included 15,865 adults who had transthoracic needle biopsy of a pulmonary nodule at a community hospital or freestanding ambulatory surgery center.

Although mortality rates didn't appear to rise with the complications, the researchers pointed to evidence that these complications were "clinically important."

Hemorrhage as a complication of needle biopsy of the lung resulted in blood transfusion in 18% of cases whereas 4.3% of patients without complications had a transfusion (P<0.001).

The complications also resulted in a higher risk of mechanical ventilation for respiratory failure: 4.3% in hemorrhage cases and 1.4% in pneumothorax requiring chest tube cases compared with 0.6% in no complication cases (P=0.017 and P=0.019, respectively).

Longer hospital stays were seen with complications in those that had the procedure done on an inpatient basis at a mean 11.6 to 17.1 days versus 10.8 days in those without a complication (P<0.001 for hemorrhage and pneumothorax requiring a chest tube).

Current or former tobacco use independently predicted a 37% elevated risk of any pneumothorax and a 50% elevated risk of pneumothorax requiring a chest tube (both P<0.001).

COPD predicted a 61% elevated risk of hemorrhage (P<0.05), an 88% elevated pneumothorax risk (P<0.001), and 2.52-fold higher risk of requiring a chest tube due to pneumothorax (P<0.001).

Age 60 to 69 was also associated with significantly higher risk compared with younger and older age at biopsy for all three types of complications.

"We suspect the lower risk for complications in younger patients [under 60] reflects a relatively healthier population, whereas the lower risk in older patients [over 70] suggests that physicians may reserve biopsy for older adults who are healthy enough to tolerate treatment if the nodule is malignant," Wiener's group explained in the paper.

The researchers cautioned about the limitations of administrative databases, which included inability to look at diagnostic yield of biopsy or long-term risks and benefits, as well as the potential for missing complications that are systematically undercoded, such as minor complications.

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