Our study is unique in that we have used the 9-point Clinical Frailty Scale as an index to assess patients for levels of frailty [21, 26]. The study demonstrates that 44.3% (137/314) of patients with lung cancer referred for Prehab in general, and 36% (n = 80/221) of lung cancer patients for surgery have frailty, which is consistent with published literature (8–10). Hence, our study suggests that a third of patients for surgery requiring Prehab are vulnerable to adverse postoperative complications, a protracted LOHS and mortality. This is in keeping with their corresponding poor dyspnoea scores, PS scores, low activity levels, significantly lower 6-MWT, DLCO and high thoracoscores at assessment for Prehab/surgery, and when compared with patients having no frailty [7, 13, 19, 20]. By providing a standardised Prehab program and improving their FI and fitness, our study shows that it is feasible to optimise elderly patients with frailty, who are considered either high risk for surgery or inoperable [27]. The duration of Prehab required is, however, significantly longer for this group of patients. Following optimisation with Prehab, our study shows that elderly patients with frailty are able to proceed with surgery with outcomes similar to patients with no frailty and considered to have low risks for adverse events or death [13, 19].

Our study takes into account that 90% of patients with FI > 3 were ever-smokers hence, likely to have underlying smoking related cardiopulmonary disease. Loss of lung tissue with surgical resection in such patients may grossly impair their post-operative ventilatory function or diffusion capability, predisposing them to dyspnoea, complications and death [19,26,28]. Hence, a comprehensive assessment of elderly patients for co-morbidity and modifiable factors is important. Our study demonstrates that with a standardised Prehab program, it is possible to improve their modifiable factors of dyspnoea, PS, LOA, FI and achieve optimisation for surgical resection with good outcomes [13, 14, 28].

The five-year survival of patient with lung cancer amongst other cancers is poor [29] and a multi-disciplinary approach is required to improve the survival of patients with lung cancer. We believe that by offering standardised Prehab to vulnerable elderly lung cancer patients with resectable disease and frailty, is one amongst other strategies that will help improve resection rates, especially as the outcomes are similar to low risk patients. Increasing the numbers of patients undergoing surgery with curative intent may contribute to improving the overall long-term survival of lung cancer patients.

Interestingly our study, in keeping with the findings of a randomized trial by Wolfram Karenovics et al. [30], shows that there were no differences in the one-year survival of patients with FI > 3 compared with patients with FI ≤ 3. However, the long-term actuarial survival at 1100 days was significantly higher for younger patients < 70 years with FI ≤ 3 compared with elderly patients ≥ 70 years with FI > 3. In our study, the follow-up days were significantly longer in the elderly group. This and an older age over time may have negatively impacted upon the long term survival of elderly patients ≥ 70 year with FI > 3, which a randomized study may help confirm.

Our study has certain limitations. This is a single-institution, pragmatic, real life provision of a standardized Prehab program to optimise lung cancer patients with frailty for surgery and may not fully address confounding factors. Objectively counting a patient’s clinical deficits for frailty, which although reproducible and correlates highly with mortality, is unwieldy [30]. Nevertheless, a randomized setting would allow such objective comparison with a control population and address confounding factors. The program is limited in its provision of service to a group of selected patients requiring optimisation prior to surgical treatment. The study is also limited in its ability to routinely re-check pulmonary functions, especially FEV1, DLCO, and cardiopulmonary exercise test (CPEX) following Prehab [19, 20, 30]. Only a small number of patients underwent CPEX testing, which was not routinely carried out. With significant improvements observed with Prehab on frailty, dyspnoea, PS, LOA and 6MWT, patients were able to proceed to surgery without requiring routine CPEX testing. The impact on economic benefits and on the quality of life of patients were not assessed, nor the disease free survival.

In conclusion, our pragmatic study demonstrates that with a standardised Prehab program, vulnerable high-risk elderly patients with high frailty index for lung resection, can be suitably optimised to proceed to safe surgical resection and have outcomes similar to low-risk patients with low frailty index. Therefore, at lung cancer MDTs the management plan for high-risk elderly patients with frailty, who are otherwise deemed vulnerable to adverse events and death, should include consideration of referral for a period of structured Prehab. Bearing in mind that optimisation with Prehab takes longer in this elderly group of patients, the duration of Prehab is guided by their stage of disease and risk of progression. Those suitably optimised with Prehab can be expected to safely proceed with curative lung resection. Nevertheless, a suitably powered randomized control trial is required to confirm our observations and establish whether a structured Prehab program helps improve the long-term survival of elderly lung cancer patients with frailty.