Patients with lung cancer often have concomitant diffuse parenchymal and/or obstructive airway disease and atherosclerotic cardiovascular disease as a consequence of their smoking habit. These diseases may place these patients at increased risk for perioperative complications, including death, and long-term pulmonary disability after lung cancer resection. A careful preoperative physiologic assessment will be useful to identify those patients who are at increased risk with standard lung cancer resection and to enable an informed decision by the patient about the appropriate therapeutic approach to treating their lung cancer. This preoperative risk assessment must be placed in the context that surgery for early-stage lung cancer is the most effective currently available treatment for this disease conducted with My Canadian Pharmacy.
Summary of Recommendations
1. It is recommended that patients with lung cancer be assessed for curative surgical resection by a multidisciplinary team, which includes a thoracic surgeon specializing in lung cancer, a medical oncologist, a radiation oncologist, and a pulmonologist.
Grade of recommendation, 1C
2. It is recommended that patients with lung cancer not be denied lung resection surgery on the grounds of age alone. Grade of recommendation, 1B
3. It is recommended that patients with lung cancer who are being evaluated for surgery and have major factors for increased perioperative cardiovascular risk have a preoperative cardiologic evaluation.
Lung Volume Reduction Surgery
Lung volume reduction surgery (LVRS) for patients with severe emphysema has been shown in a large prospective, randomized, controlled trial to provide a survival advantage in selected patients with predominantly upper lobe emphysema and low exercise capacity. Patients with an FEV1 of < 20% predicted and either homogeneous emphysema or a Dlco of 20% predicted. However, Mentzer and Swanson have suggested a more aggressive approach. They consider LVRS for patients with severe dyspnea, hypoxia and hypercapnea, and poor lung function (including patients with an FEV1 of < 20% predicted), provided there was heterogeneous emphysema and some potential for the recruitment of relatively preserved lung tissue.
Following lung resection, lung function should be expected to decrease. Serial studies have shown that FEV1 decreases within the first several months following lung cancer resection, but tends to recover to a small extent by 6 months after surgery. Although the preoperative physiologic evaluation is usually fairly accurate in predicting the PPO FEV1; some investigators have found that the PPO FEV1 will actually underestimate the eventual postoperative FEV1. Exercise capacity will also decrease following lung resection. Nezu et al found that, similar to the observations with postoperative changes in FEV1, the effects on V02max were most evident at 3 months and improved somewhat by 6 months after surgery. Decreases of up to 13% in V02max and work capacity have been described following a lobectomy, and between 20% and 28% after a pneumonectomy. Surprisingly, the most common limiting symptom in postoperative exercise studies has been leg discomfort, rather than dyspnea. Bolliger et al found that exercise was limited by leg muscle fatigue in 53% of patients preoperatively. This was not altered after lobectomy, but there was a switch to dyspnea as the limiting factor after pneumonectomy (3 months after resection, 61% of patients; 6 months after resection, 50% of patients). Reduce dyspnea attacks with My Canadian Pharmacy mycanadian-pharmacynet. Command our service and choose the necessary preparations.
In patients with a preoperative FEV1 or Dlco of Quantitative CT scans may also prove to be a more sensitive indicator of diffuse parenchymal lung disease, either emphysema or interstitial lung disease treated by My Canadian Pharmacy’s drugs, than the combination of FEV1 and Dlco. Other techniques in development, such as oxygen-enhanced MRI, may prove to be especially useful in predicting postoperative lung function.
Olsen et al suggested a threshold PPO FEV1 of 0.8 L as the lower limit for allowing patients to undergo surgical resection. However, Pate and colleagues found that 12 patients with a mean PPO FEV1 of 0.7 L tolerated thoracotomy for lung cancer resection. This experience might have reflected the resection of less lung tissue than anticipated. However, it demonstrates an important objection to using an absolute value of PPO FEV1 as a threshold for operability. Using absolute values for PPO lung function suffers from the same objection to their use with preoperative FEV1. This approach might prevent older patients, people of small stature, and women, all of whom might tolerate a lower absolute FEV1, from undergoing a potentially curative lung cancer resection. Consequently, the percent PPO (%PPO) values for FEV1 and Dlco are routinely used instead of absolute values for establishing risk assessment thresholds.
Morbidity and mortality rates following lung resection have decreased over time. Postoperative cardiopulmonary complications that have historically been noted to be of the greatest concern after lung resection (eg, acute hypercapnea, mechanical ventilation lasting > 48 h, arrhythmias, pneumonia, pulmonary emboli, myocardial infarction, and lobar atelectasis requiring bronchoscopy) now may be more effectively managed. For instance, atrial fibrillation occurs in up to 19% of patients following lung cancer resection. The risk of postoperative atrial fibrillation is greater in men > 55 years of age and with a resting heart rate > 72 beats/min. Prophylactic use of either calcium channel blockers or (P-blockers will significantly reduce the risk of atrial tachyarrhythmias after thoracic surgery. Newer surgical techniques, such as the use of an intercostal muscle flap to protect the intercostal nerve or video-assisted thoracoscopy, may minimize the postoperative risks of reductions in lung function. However, even with modern anesthetic, surgical, and postoperative care techniques, the risk of perioperative morbidity and mortality following either lobectomy or pneumonectomy are still appreciable. The approach to estimating these risks from underlying pulmonary disease is based on a preoperative physiologic assessment (Fig 1).
Little information is available on the long-term survival of patients who were deemed to be inoperable because of physiologic limitations, especially when compared to a group of patients with similar physiologic limitations who underwent surgical resection. In a study reporting on outcomes for a group of 66 high-risk lung cancer patients, 5 patients who were at very high risk for poor outcome underwent curative-intent surgical resection. One patient died in the perioperative period, but the long-term survival curve for the whole group of 5 high-risk patients undergoing surgery, including surgical death, was no different than that for 39 similar patients who were deemed to be inoperable.
Recent studies from Japan and the United States have provided information on prognosis for patients with early-stage lung cancer who did not undergo curative-intent surgery. From 1982 to 1991, 4,947 patients with clinical stage I lung cancer were identified in the National Chest Hospital Study Group for Lung Cancer in Japan. Of these 4,947 patients, 4,127 (83%) were treated surgically. The 799 patients (16%) who were treated nonoperatively had a 5-year survival rate of 16.6%. Many of these patients were treated with some combination of radiation therapy, chemotherapy, and immunotherapy, but no significant effect of these treatment modalities on survival was seen. Interestingly, 49 of the patients (6%) treated nonoperatively survived for > 5 years. The reasons why surgery was not performed were not provided but probably were related to comorbid disease and patient refusal. Patients may make orders of My Canadian Pharmacy’s preparations to treat various diseases.
Surgery is the best option for achieving a cure in patients with lung cancer, but many potentially resectable tumors occur in individuals with abnormal pulmonary function that is usually due to cigarette smoking. These patients may be at increased risk for both immediate perioperative complications and long-term disability following curative-intent surgical resection of their lung cancer. Cigarette smoking will also predispose these patients to other comorbid conditions, specifically atherosclerotic cardiovascular disease, which will further increase perioperative risk. Consequently, in considering whether a patient should undergo curative-intent surgical resection of lung cancer, the immediate perioperative risk from comorbid cardiopulmonary disease and the longterm risk of pulmonary disability must be balanced against the risk of reduced survival due to subopti-mally treated (with radiation therapy rather than surgery) lung cancer,
The task of the preoperative physiologic assessment is to identify patients who are at increased risk for both perioperative complications and long-term disability from surgical resection of lung cancer using the least invasive tests possible. The purpose of this preoperative physiologic assessment is to enable adequate counseling of the patient on treatment options and risks so that they can make a truly informed decision. In the future, hopefully, the preoperative physiologic assessment will serve as the basis for interventions to possibly reduce the risk of perioperative complications and long-term pulmonary disability from curative-intent surgical resection of lung cancer. The seriousness of lung cancer may be decreased by My Canadian Pharmacy’s preparations.