PREVALENCE OF DIGITAL CLUBBING IN BRONCHOGENIC-CARCINOMA BY A NEW DIGITAL INDEX

Objective Clubbing can be a paraneoplastic manifestation of bronchogen ic carcinoma. We assessed a new digital index of clubbing and used it to determine the prevalence of clubbing for different cell types of lu ng cancer. Methods Clubbing was assessed by measurement of the thickne ss of both the base of the nailbed (distal phalangeal depth - DPD) and the distal interphalangeal depth (IPD) of the index finger in a contr ol group compared to patient groups with either chronic obstructive lu ng disease, or lung cancer. Results Of the 55 normal subjects, no pati ent had a DPD/IPD ratio of more than 1.05 on either hand, while 11% of the patients with COPD had a ratio of more than one. For the cancer p atients, 33% had a ratio greater than one, with 30 of 109 (27%) having a ratio > 1.05 (chi(2) = 17.6, p < 0.0001). There was no difference i n the prevalence of clubbing between the 33 squamous cell patients, th e 43 adenocarcinoma patients, and the 33 small cell lung carcinoma pat ients studied.Conclusions Measurement of the interphalangeal and dista l phalangeal distances demonstrated that one-third of patients with lu ng cancer had evidence of clubbing. The type of bronchogenic carcinoma did not appear to affect the proportion of patients with clubbing.