The aim of this study was to analyze whether there are surnames which appea
r more frequently among the ancestors of cancer cases in a small isolate, i
n comparison to the ancestral surnames of the healthy controls, using the c
lassic case-control design. The chosen setting was the island of Lastovo, C
roatia, located more than 100 Kilometers from the nearest coastal region. T
he period of study was 1970-1995, during which a total of 76 cancer cases w
ere recorded in a population of approximately 800. The comparison of surnam
e frequencies was performed in current and in five ancestral generations. T
he leading hypothesis was that, if inbreeding and common ancestry contribut
ed to the development of the disease, then those phenomena should be reflec
ted in, increasing frequency of some surnames among ancestors, identifying
the 'hidden' consanguinity, or 'following' cancer-promoting genes on the Y-
chromosome. The results imply that there are surnames representing a classi
c "risk" for cancer but also those "protecting" from its development, which
all underscores the importance of founder effect and genetic predispositio
n to the disease in a small, reproductively isolated population. All of the
results become more evident and increasingly significant when analyzed in
more distant ancestral generations.