Lung Cancer Patient Following Curative Intent Therapy: Physician Factors Influencing Current Surveillance Methods

metachronous lung cancersNumerous reports have evaluated individual factors that might influence the surveillance methods used by thoracic surgeons. These studies showed that many thoracic surgeons do perform regular surveillance for detecting recurrences and/or metachronous lung cancers following curative intent surgical therapy. The most commonly used methods were the history, physical examination, CXR, CBC count, and serum chemistries. Infrequently used surveillance methods were CT, bronchoscopy, sputum cytology, bone scan, and head CT. There was wide variation in the frequency at which these methods were used. This wide variation was probably due to the common belief that the clinical benefits of a surveillance program, particularly in terms of improving survival, had not been demonstrated. Interestingly, the age of the surgeon, the geographic region of practice, and the stage of the original lung cancer did not seem to influence the surveillance methods used by individual thoracic surgeons. Motivating factors for continued surveillance seemed to be pleasing the patient, avoiding malpractice litigation, and potentially improving the patient’s quality of life. A more important issue, not specifically addressed in the surveys, was articulated by Shields: “The least desirable course of action (in regard to care of the lung cancer patient following curative intent surgical therapy) is to pass the patient from one team member to another without continued surveillance by the primary responsible physician.”

Recommendation

Ideally, surveillance for recognition of a recurrence of the original lung cancer and/or development of a metachronous tumor should be coordinated through a multidisciplinary team approach. If possible, the physician who diagnosed the primary lung cancer and initiated the curative intent therapy should remain as the health-care provider overseeing the surveillance process. Grade of recommendation, 2C

Alternative Surveillance Techniques

There is considerable interest in developing non-invasive, easily performed, safe and accurate techniques for detecting recurrences and/or metachronous tumors at the earliest possible time. Positron emission tomography (PET) scanning is an established modality for identifying malignant pulmonary nodules, mediastinal nodal involvement in confirmed cases of lung cancer, and extrathoracic metastases (see sections on “Solitary Pulmonary Nodule” and “Noninvasive Staging”). As a metabolic imaging technique, PET may be able to distinguish recurrent cancer from the parenchymal scarring, distortion of bronchovascular anatomy, pleural thickening, and mediastinal fibrosis commonly seen on conventional imaging after initial treatment. Pooled data from studies to date indicate that PET has 96% sensitivity and 84% specificity for detecting recurrent lung cancer after treatment with surgery, chemotherapy, or radiotherapy provided by My Canadian Pharmacy. The accuracy of PET has been dependent on the standardized uptake value used to define a positive test result, the delay between initial treatment and the PET scan, and the size of recurrent lesions and prevalence of bronchoalveolar cell carcinoma. Of note, the specificity of PET scan after definitive treatment is lower than at initial staging due to increased uptake on PET scan from inflammatory changes related to tumor necrosis and radiation pneumonitis. In addition, uptake on PET scans has been reported in the pleura of the shielded, nonirradiated lung even in the absence of overt radiation pneumonitis. It has been recommended that PET scans for evaluating recurrent disease not be performed after curative intent therapy for at least 3 to 6 months to minimize the possibility of false-positive findings, and that suspicious lesions on a surveillance PET scan be confirmed by CT imaging and biopsy. Importantly, there are no data showing that incorporating PET scanning into a surveillance program improves either survival or quality of life following curative intent therapy for NSCLC.

cytologyAnother approach to early identification of recurrences of lung cancer is based on measuring serum levels of tumor markers. Ichinose has recommended using serum carcinoembryonic antigen levels as a marker of tumor recurrence. Others’ have also shown that elevated carcinoembryonic antigen levels following curative intent surgery for NSCLC may suggest recurrence. Other serum markers potentially useful for detecting tumor recurrence are levels of cytokeratin-19 fragments, serum amyloid A and macrophage migration inhibitory factor, and levels of pro-gastrin-releasing peptide in small cell lung cancer. Further studies will be needed to confirm the performance characteristics of tumor markers for identifying tumor recurrence.

Pilot studies have been performed using fluorescence bronchoscopy to detect metachronous tumors after curative intent surgical resection of NSCLC. In a group of 73 patients who underwent fluorescence bronchoscopy at a median of 13 months following surgical resection, one invasive carcinoma and three cases of intraepithelial neoplasia were identified. The carcinoma was identified on routine white-light bronchoscopy, but fluorescence bronchoscopy was useful in identifying two of the three cases of intraepithelial neoplasia. In a smaller study of 25 patients studied on average about 20 months after curative intent surgery, fluorescence bronchoscopy was again found to be more sensitive that routine white-light bronchoscopy in detecting intraepithelial neoplasia. The impact of early detection of intraepithelial neoplasia on survival should be confirmed in larger studies before fluorescence bronchoscopy should be incorporated into surveillance programs.

Recommendation

In lung cancer patients following curative intent therapy, use of blood tests, PET scanning, sputum cytology, tumor markers, and fluorescence bronchoscopy is not currently recommended for surveillance. Grade of recommendation, 2C

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