Systematic review
The systematic review included 148 articles (mostly case and case series
reports), with a total of 381 cases of LCS (Figure 7). In 2 of them
(0.5%) the authors described the coexistence of LCS associated to a
PTC. None of them had cervical metastasis. In terms of quality, the
articles were classified within medium quality values.
The sample consisted of 254 men (74.3%) and 88 women (25.7%) with a
mean age of 61.1 ± 12.1. Diverse symptoms were described in 325 patients
(85.3%). A different grade of dyspnea was the most commonly reported
symptom (42.8%) followed by hoarseness (35.7%) and neck mass sensation
(10.8%). Most of the patients reported more than one symptom.
Impairment of at least one vocal cord mobility was reported in 66
patients (17.3%). Imaging studies were described in 213 patients
(55,9%). CT scan was the most commonly used, in 209 patients, followed
by MRI in 46. Other techniques as ultrasound or X-ray were also
described. In Figure 8, more information regarding demographics,
symptomatology, location, and imaging is provided.
Tumoral location was reported in 340 patients (89.2%). The cricoid
cartilage was the most commonly affected with 271 cases (79.9%),
followed by the thyroid cartilage in 67 cases (19.7%). In 41 patients
(10.8%) the tumor involved more than one anatomical site. Different
treatment modalities were used. Total laryngectomy was reported in 131
patients (34.4%), local excision in 104 cases (27.3%), partial
laryngectomy in 92 (24.1%), and laser surgery in 34 patients (8.9%).
Uni or bilateral neck dissection was reported in 18 cases (4.7%). First
choice radiotherapy was used in 7 patients (1.8%). Adjuvant therapy
with RT was described in 28 patients (7.34%) and chemotherapy in 2
patients (0.52%). The size of the tumor was reported in 135 patients
(35.4%), being the mean size 3.8 ± 1.7 cm. Histological information was
found in 323 patients (84.7%). Pathological grading was reported as
Grade I (well-differentiated) in 210 cases (67.1%), Grade II
(moderately-differentiated) in 62 cases (19.8%), Grade III (poorly
differentiated) in 8 cases (2.6%) and Grade IV (dedifferentiated) in 18
cases (5.8%). Other cases were reported as clear cell CS, or myxoid CS.
Distant metastases were unfrequent, and appeared in 21 patients (5.5%)
in different locations like lungs, soft tissue, bone or peritoneum. Lung
metastasis was the most frequent location, being present in 15 cases
(71.4 %). The mean follow-up time was 57.7 ± 53.4 months. In this
period, tumoral recurrence was reported in 62 cases (16.3%). Total
Laryngectomy was the treatment of choice in 25 of the recurrences
(6,6%). Local excision and laser were used in 18 patients (4.7%) while
partial laryngectomy was described in 8 patients (2.1%). Death was
reported in 47 patients (12.3%), mostly as “not related or other
cause” (74%), or “distant metastasis” (17,4%). Only 8.7%
were reported as “dead of disease” . Death was found to be more
frequent in those patients with tumoral recurrence who were treated with
total laryngectomy (55.3%, p = 0.001). In Figure 9 additional
information about treatment, tumoral characteristics, and follow-up
period is provided.
Using Kaplan-Meier curves, a mean survival of 207.5 months (95% CI
176.4-238.7 months) is estimated (Figure 10). Regarding survival in
relation with tumoral location, the estimate is lower for those cases
with combined location, with 98.5 months (95% CI 73-124 months)
compared to those affecting only one location, with a mean of 191.6
months (95% CI 163.1-220 months) (log-rank = 6.6, p = 0.01) (Figure
11). Survival is also affected by histological differentiation, being
the lowest for grade IV (dedifferentiated) with 118.7 months (95% CI
64.8-172.6 months) and the longest for grade I (well-differentiated)
with 253.8 months (95% CI 215-292.5 months) (log-rank = 18.3; p =
0.003) (Figure 12).
Taking into account treatment modality, the estimate for survival is
lower for those who underwent total laryngectomy with 156.6 months (95%
CI 127.5-185.6 months) compared with those who were treated with laser
excision with 276.1 months (95% CI 229.4-322.9) (log-rank = 11.7;
p=0.008) (Figure 13).