Lascano, or Lazcano (remember, spelling was not uniform many years ago), is a Basque name from Spain. There used to be a Lascano family on Guam for many years. They were here from at least 1758 until the early 1900s.
A Pampanga (Filipino) soldier by the name of Manuel Francisco Lascano was on Guam in 1758, married to what I suspect was a Chamorro wife named Maria Lucia Mamingin. By 1758, they had four boys, no girls. You would think that this was a good sign that the family name would survive.
However, by 1897, there were only two people on the island with the Lascano last name. One was an elderly man in Hågat named Policarpio Pinaula Lascano, married to Maria Dueñas de la Cruz. Policarpio's father was from Humåtak. Apparently, Policarpio and Maria (in their late 40s) had no children.
Then, in Humåtak, there was in 1897 a widow named Maria Lascano, whose deceased husband was Geronimo Aguon*. There were other Lascanos, all women, who married into the Aguon, Tajalle and Quinata families. A prevalence of girls in the family lead to the disappearance of the surname. It survived only as a middle name until sixty years ago or so, and overwhelmingly in Humåtak.
*See my post on "Geronimo" as a first name.