Keywords
geriatric services - thoracic surgery - in-hospital mortality - lung cancer
Introduction
Patients undergoing thoracic surgery often have multiple comorbidities and a strong
smoking history that increases the risk of major surgery.[1] Furthermore, the increasing longevity of the Western population means patients with
a more advanced age are being diagnosed with resectable disease and referred for surgery.[2] Improvements in imaging and diagnostic capabilities and with the possibility of
lung cancer staging, this trend is likely to develop further.[3]
There is a paucity of evidence to guide surgical decision making in the elderly, particularly
in thoracic surgery, due to underrepresentation in clinical trials. Historically,
only 25% of the trials have been open to patients older than 65 years.[4] However, recent studies are demonstrating low levels of mortality when operating
on this group of patients.[5]
[6] The ACOSOG Z0030 trial showed that there was no increase mortality risk when performing
lobectomies in an older cohort.[7] Surgery has even been shown to demonstrate an increase in survival compared with
radiotherapy in this cohort.[8]
Age itself is not a contraindication for surgery, nor should it be, although it is
understood that it can be a marker of decreased physiological and mental compliance,
often proportional to comorbidities.[9] Physiological decline, multimorbidity, and frailty are independent predictors that
are associated with aging.[10]
[11]
[12] Age has been demonstrated to be a risk factor itself and is therefore used in the
common risk stratification algorithms for thoracic surgery.[13] Despite this, patients can present with preserved physiology as measured by lung
function testing and echocardiography yet are outside the normal range traditionally
considered for major surgery on the basis of age.[14] This alongside the overall reduction in mortality associated with thoracic surgery
in the current era, possibly due to advances in anesthetic and surgical techniques,
and perioperative optimization and enhanced recovery, these patients are now being
considered as surgical candidates.[15] Furthermore, collaboration with specialist geriatric liaison services has shown
to further reduce postoperative complications in the elderly population undergoing
surgery.[16]
The Getting It Right First Time (GIRFT) program produces a report of data obtained
from units nationally to identify changes between centers with the aim to reduce unwanted
variations.[17] As a unit that had been identified in the GIRFT report as an outlier for operating
on an elderly population, our objective was to retrospectively assess the outcomes
of patients older than 85 years in our unit who had been treated with elective lung
resection for early-stage non-small cell lung cancer (NSCLC) and were older than 85
years at the time of surgery.[17]
Materials and Methods
We analyzed and compared all patients who underwent elective lung resection between
the 4-year period of 2012 and 2015 who were aged between 80 and 84 years and 85 years
and older at the time of surgery. These patients were identified from the National
Thoracic Surgical Database. The electronic patient records were then used to obtain
data for patient demographics, date of surgery, date of death, age at death, operation
type, smoking history, and comorbidities (renal, cardiac, respiratory, and neurological).
Death within 30 days of surgery within the same in-hospital episode was the definition
of in-hospital mortality. Cause of death was determined as the significant pathological
insult that was ultimately responsible for the patient's decline (i.e., hospital-acquired
pneumonia). The Thoracic Surgery Scoring System (Thoracoscore) was used to estimate
perioperative mortality based on these data.[13]
Results
A total of 701 elective lung resections were performed for NSCLC in this time frame
by five different surgeons. Seventy-six patients were between the age of 80 and 84
years and 18 patients were older than 85 years. The follow-up period was 3 to 7 years.
There was a significant increase in the Thoracoscore (2.04; 2.96%, p = 0.0015) and a significant reduction in the transfer factor (94.7; 69.5%, p = 0.0001) between the younger and older groups. The main differences between the
two groups are summarized in [Table 1].
Table 1
Summary of differences between the two groups
Age group
|
80–84 y
|
85+ y
|
|
N (% of all resections)
|
76 (10.8%)
|
18 (2.6%)
|
|
Mean age
|
81.8 (80–84)
|
87.5 (85–92)
|
|
Male:female ratio
|
35:41
|
10:8
|
p = 0.47
|
Thoracoscore
|
2.04
|
2.96
|
p
= 0.0015
|
TLCO
|
94.7%
|
69.5%
|
p
= 0.00013
|
Number of in-hospital deaths
|
3 (3.94%)
|
0
|
p = 0.8
|
90 d mortality
|
4 (5.3%)
|
1 (5.6%)
|
p = 0.96
|
Deaths in follow-up period
|
25 (33%)
|
7 (39%)
|
p = 0.63
|
Number VATS procedure
|
45 (59.2%)
|
7 (39%)
|
p = 0.12
|
Number of wedge/segmental resections
|
15 (19.7%)
|
6 (33.3%)
|
p = 0.21
|
Abbreviations: Thoracoscore, Thoracic Surgery Scoring System; TLCO, transfer factor
of the lung for carbon monoxide; VATS, video-assisted thoracic surgery.
Note: Significant p values are in bold.
In the 80 to 84 years age group, all 76 (100%) patients were smokers or ex-smokers
and 17 (22.3%) patients had no previous medical history. Two (2.6%) patients had had
previous lobectomies for NSCLC. Preoperatively, six (7.9%) patients had atrial fibrillation
(AF), and seven (9.2%) were diabetic. Forty-nine (64.4%) lobectomies, 5 (6.6%) segmentectomies,
15 (19.7%) wedge resections, 2 (2.6%) lobectomies with wedge resections, 1 (1.3%)
bilobectomy, 2 (2.6%) pneumonectomies, and 2 (2.6%) lobectomies with chest wall resection
were performed. None of the 45 (59.2%) video-assisted thoracic surgery (VATS) procedures
required conversion. Sixty-four (84.2%) patients were pathologically in stages 1 to
2 with 8 (10.5%) patients found to be in stage 3a (4 [5.3%] with N2 disease), and
4 (5.3%) patients with stage 3b disease. There were three (3.9%) in-hospital deaths
(two [2.6%] from respiratory failure and one [1.3%] from stroke), three (3.9%) prolonged
air leaks, two (2.6%) pulmonary emboli, five (6.6%) lower respiratory infections,
and one (1.3%) upper gastrointestinal bleed. Four (5.3%) patients died within 90 days
of surgery (three in-hospital deaths).
In the 85 years and older age group, all 18 (100%) patients were smokers or ex-smokers
and 1 (5.6%) patient had no previous medical history. Two (11.1%) patients had had
previous lobectomies for NSCLC. Preoperatively, six (33.3%) patients had AF, and three
(16.7%) were diabetic. Nine (50%) lobectomies, 6 (33.3%) wedge resections, 2 (11.1%)
lobectomies with wedge resections, and 1 (5.6%) lobectomy with chest wall resection
were performed. None of the seven (38.9%) VATS procedures required conversion. Sixteen
(88.9%) patients were pathologically in stages 1 to 2 with two (11.1%) patients found
to be in stage 3a (N2 disease). One (5.6%) patient returned to the operating room
for bleeding, one (5.6%) patient required inotropes and intensive treatment unit stay
for chest sepsis, and two (11.1%) patients had prolonged air leaks. There were no
in-hospital deaths in this group and one (5.6%) death within 90 days of surgery.
The component that increased the Thoracoscore in the 85 years and older age group
was the comorbidity score. The mean comorbidity score for the 85years and older age
group was 2.6 compared with 1.3 for the 80 to 84 years age group. This difference
was statistically significant (p < 0.001). There was no significant difference between sex, performance status, dyspnea
score, and procedure type. All patients scored equally for disease type (malignant),
age (older than 65 years), and priority of surgery (elective).
Discussion
Lung cancer is a disease that affects older population.[4] Currently, there is evidence that despite an aging population, patients older than
75 years have almost a fourfold chance of being turned down for surgery compared with
those younger than 65 years despite having earlier stage tumors.[18] This is an understandable trend as these elderly patients have been shown to have
longer inpatient stays and are associated with increased mortality risk.[19]
With increasing evidence that surgery may be appropriate in the elderly, but paucity
of specific evidence and lack of well-validated risk scores, the challenge lies in
deciding who is an appropriate candidate for surgery. Conventional risk models are
not accurately calibrated to predict outcomes in the elderly and do not include frailty
parameters.[13]
Frailty scores have been shown to correlate with negative outcomes across all surgery
types. Greater mortality at 30 days, 90 days, and 1 year, along with increased postoperative
complications and lengths of stay, has been observed (20). Several studies agree that
increase in risk of mortality with increased frailty is around twofold.[20]
[21]
[22] There are many plausible mechanisms for this that include reduced physiological
reserve, which increases the risk of deterioration, and reduced cognitive function,
which increases the risk of delirium.[23]
Among the limited thoracic surgery-specific data, there is some suggestion that frailty
may be even more strongly associated with adverse outcomes than in other specialties,
with a four- to sevenfold increase in mortality risk reported, and therefore, risk
models incorporating frailty scores have been developed, such as FORECAST (Frailty
predicts death One year after Elective Cardiac Surgery Test); however, they need more
thorough validation.[24] It has been highlighted that a single frailty measure alone does not predict an
increase in morbidity and mortality, but a combination of several measures may be
able to.[25]
Despite its limitations, the Thoracoscore demonstrated that there was a significant
increase in risk difference between the two groups in this study. It is therefore
imperative that risk reduction strategies are employed to decrease the morbidity and
mortality burden. Specialized geriatric services have been developed to try and achieve
this with good results. These results have been demonstrated in vascular surgery where
preoperative thorough assessment has shown to diagnose and predict cognitive impairment,
frailty, and postoperative delirium.[26]
[27] It is therefore essential that these services continue to develop and extend into
thoracic surgery.
Lobectomy has been the treatment of choice in lung cancer surgery in the suitable
patients for its benefit in terms of reduced recurrence rates; however, the evidence
for this is now dated.[28] However, there is now a growing body of evidence that demonstrates equivalence in
smaller, suitable tumors in terms of oncological outcomes.[29] Therefore, it is understandable that these parenchymal-sparing procedures are being
utilized more frequently, as in this study, in the higher risk, elderly patient.
A surprise finding in this study was the high proportion of elderly patient undergoing
thoracotomy and lung resection compared with the use of VATS. VATS has been shown
to reduce surgical stress, impact on chest wall mechanics, morbidity and mortality,
pain, and postoperative delirium.[30] This finding is not statistically significant and it is difficult to explain the
cause. The failure to reach significance may be as a result of the small population
size, especially of the 85 years and older age group, or be a chance finding. If the
former is true, a potential explanation may be the reluctance to perform VATS in patients
who are perceived by the surgeons to be higher risk due to age. A thoracotomy in this
setting may have been felt to have been the safer option.
Much of the work in the literature is directed at the 80 years and older age group;
however, this study highlights that it is safe to operate in the group that lie beyond
this, the 85 years and older age group. This is despite knowing that they are both
measurably, using the Thoracoscore, and immeasurably, due to frailty and physiological
decline, at higher risk of morbidity and mortality.
Limitations of the Study
This study only analyzed patients who underwent surgery at our institution. Further
work is required to analyze all the patients in these age groups who presented with
operable lung cancer and determine the reasons that surgery was not performed.
There has been no analysis of specific oncological outcomes such as recurrence or
disease-free survival in the study. However, due to there being no significant difference
between the groups in terms of approach or extent of resection, the authors did not
feel that this was necessary.
This study is a retrospective review and therefore subject to observational bias.
Conclusion
This study demonstrates that surgery for early NSCLC can be safely performed in 85
years and older population. This must occur in the knowledge that this is a higher
risk population due to increased comorbidities as demonstrated in this study and parenchymal-sparing
procedures should be considered. Further work is required to incorporate old age physiology
and frailty into risk assessment models to aid with perioperative decision making.
Input from specialist geriatric teams may prove to be helpful in managing these patients.