Guanzon started as an anchorman and one of the pioneering members of
DZAQ Radyo Patrol of
ABS-CBN from 1968 until it was shut down due to
martial law declaration. He later became anchor of radio stations
DZXL and
DZBB ("Tawag Pansin") in the 1980s and in
DWWW in the 1990s. It is also had a TV version aired on
BBC before the
People Power Revolution. Guanzon also ventured into television as an anchor of
GMA Balita, the network's first flagship Filipino newscast and
Kape at Balita, the first simultaneous radio-TV morning commentary show, both aired on
GMA Network. He also anchored
Teledyaryo,
Isyu Ngayon and
Tinig ng Bayan on
NBN. In the recent years, he became part of
DZRM Radyo Magasin as the anchor of "Gabay at Balita". Guanzon was elected as congressman of the
1st district of
Caloocan, serving for one term from 1995 to 1998. He ran again in the same elected position in
2010 and
2013, this time as an independent candidate, but lost. ==Illness and death==