Merkel Cell Carcinoma: The Sydney Experience

Factor

Value

Patient sex

Male

Female

Age at initial diagnosis

(years)

Median = 74 (range 47–88)

Immunocompromised at initial diagnosis

Yes

Types of immunosuppression

Long-term steroids

Transplantation

Primary site of MCC

Head and neck

Upper limb

Lower limb

Trunk

Buttocks

Not known

Primary macroscopic size

(mm)

n = 53; median = 15 (range 5–60 mm)

Stage

III

Lymphadenectomy

Yes

Final surgical treatment for primary

Incisional biopsy

Excisional biopsy

WLE

Not applicable

Adjuvant RT to the primary site

Yes

Not applicable

RT to the regional node site

Yes

Local recurrence

Yes

53^a

Regional recurrence

Yes

Distant recurrence

Yes

Not known

Status at last follow-up

Alive

Died of disease

Died of other/unknown

^aOut of 53 with no local recurrence, 9 unknown primaries are included

12.3.2 Recurrences

Nine patients (14 %) experienced a local recurrence of their MCC. Sixteen (26 %) developed a regional recurrence; all locoregional recurrences were observed in stage I or II patients. No stage III patients had regional relapses observed with a median follow-up of 44 months (range 7–115 months). Distant recurrence status was known for 57 patients and, of these, 16 (28 %) recurred in a distant site (11 stage I/II; 5 stage III).

12.3.3 Impact of RT to the Primary Site

Local recurrence-free survival was assessed. For the subset of 42 stage I and II patients, those that had RT to their primary site (n = 32) had a 2-year local recurrence-free survival of 89 % compared with 36 % for patients (n = 10) not receiving RT (Fig. 12.1, p < 0.001).

Fig. 12.1

Local recurrence-free survival of 42 stage I and II patients

Disease-free survival for RT to primary site was assessed. Disease-free survival (DFS) was significantly improved for patients having RT to their primary site. This result was observed in the overall cohort (Fig. 12.3, p = 0.009) and also the subset of patients having stage I and II disease (p = 0.048). For the overall cohort, the cumulative 2-year DFS was 54 % for the RT group compared with 25 % for the no-RT group (Fig. 12.2).